diff --git a/src/Tokenizers/Tokenizer.php b/src/Tokenizers/Tokenizer.php
index 68238d3023..aa706fbfa9 100644
--- a/src/Tokenizers/Tokenizer.php
+++ b/src/Tokenizers/Tokenizer.php
@@ -620,7 +620,7 @@ public function replaceTabsInToken(&$token, $prefix=' ', $padding=' ', $tabWidth
                 if ($content !== '') {
                     $newContent .= $content;
                     if ($checkEncoding === true) {
-                        // Not using the default encoding, so take a bit more care.
+                        // Not using ASCII encoding, so take a bit more care.
                         $oldLevel = error_reporting();
                         error_reporting(0);
                         $contentLength = iconv_strlen($content, $this->config->encoding);
diff --git a/tests/Core/Tokenizers/Tokenizer/CreatePositionMapTabWidth0Test.php b/tests/Core/Tokenizers/Tokenizer/CreatePositionMapTabWidth0Test.php
new file mode 100644
index 0000000000..fd47bf7da5
--- /dev/null
+++ b/tests/Core/Tokenizers/Tokenizer/CreatePositionMapTabWidth0Test.php
@@ -0,0 +1,107 @@
+<?php
+/**
+ * Tests the tab replacement logic.
+ *
+ * @author    Juliette Reinders Folmer <phpcs_nospam@adviesenzo.nl>
+ * @copyright 2024 PHPCSStandards and contributors
+ * @license   https://github.com/PHPCSStandards/PHP_CodeSniffer/blob/master/licence.txt BSD Licence
+ */
+
+namespace PHP_CodeSniffer\Tests\Core\Tokenizers\Tokenizer;
+
+/**
+ * Tab replacement test using tab width 0, means no tab replacement will take place.
+ *
+ * @covers PHP_CodeSniffer\Tokenizers\Tokenizer::createPositionMap
+ */
+final class CreatePositionMapTabWidth0Test extends ReplaceTabsInTokenTestCase
+{
+
+    /**
+     * The tab width setting to use when tokenizing the file.
+     *
+     * @var integer
+     */
+    protected $tabWidth = 0;
+
+
+    /**
+     * Data provider helper.
+     *
+     * @see ReplaceTabsInTokenTestCase::dataTabReplacement()
+     *
+     * @return array<string, array<string, int|string|null>>
+     */
+    public static function getTabReplacementExpected()
+    {
+        return [
+            'Tab indentation'                                                      => [
+                'length'       => 2,
+                'content'      => '		',
+                'orig_content' => null,
+            ],
+            'Mixed tab/space indentation'                                          => [
+                'length'       => 3,
+                'content'      => '	  ',
+                'orig_content' => null,
+            ],
+            'Inline: single tab in text string'                                    => [
+                'length'       => 15,
+                'content'      => "'tab	separated'",
+                'orig_content' => null,
+            ],
+            'Inline: single tab between each word in text string'                  => [
+                'length'       => 24,
+                'content'      => '"tab	$between	each	word"',
+                'orig_content' => null,
+            ],
+            'Inline: multiple tabs in heredoc'                                     => [
+                'length'       => 15,
+                'content'      => 'tab			separated
+',
+                'orig_content' => null,
+            ],
+            'Inline: multiple tabs between each word in nowdoc'                    => [
+                'length'       => 27,
+                'content'      => 'tab		between				each			word
+',
+                'orig_content' => null,
+            ],
+            'Inline: mixed spaces/tabs in text string'                             => [
+                'length'       => 20,
+                'content'      => "'tab 	  		separated'",
+                'orig_content' => null,
+            ],
+            'Inline: mixed spaces/tabs between each word in text string'           => [
+                'length'       => 31,
+                'content'      => '"tab	 $between  	each	   	word"',
+                'orig_content' => null,
+            ],
+            'Inline: tab becomes single space in comment (with tabwidth 4)'        => [
+                'length'       => 50,
+                'content'      => '// -123	With tabwidth 4, the tab size should be 1.
+',
+                'orig_content' => null,
+            ],
+            'Inline: tab becomes 2 spaces in comment (with tabwidth 4)'            => [
+                'length'       => 52,
+                'content'      => '/* -12	With tabwidth 4, the tab size should be 2. */',
+                'orig_content' => null,
+            ],
+            'Inline: tab becomes 3 spaces in doc comment string (with tabwidth 4)' => [
+                'length'       => 45,
+                'content'      => '-1	With tabwidth 4, the tab size should be 3.',
+                'orig_content' => null,
+            ],
+            'Inline: tab becomes 4 spaces in comment (with tabwidth 4)'            => [
+                'length'       => 47,
+                'content'      => '// -	With tabwidth 4, the tab size should be 4.
+',
+                'orig_content' => null,
+            ],
+        ];
+
+    }//end getTabReplacementExpected()
+
+
+}//end class
diff --git a/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenMiscTest.php b/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenMiscTest.php
new file mode 100644
index 0000000000..f4bd711a6f
--- /dev/null
+++ b/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenMiscTest.php
@@ -0,0 +1,124 @@
+<?php
+/**
+ * Tests the tab replacement logic.
+ *
+ * @author    Juliette Reinders Folmer <phpcs_nospam@adviesenzo.nl>
+ * @copyright 2024 PHPCSStandards and contributors
+ * @license   https://github.com/PHPCSStandards/PHP_CodeSniffer/blob/master/licence.txt BSD Licence
+ */
+
+namespace PHP_CodeSniffer\Tests\Core\Tokenizers\Tokenizer;
+
+use PHP_CodeSniffer\Files\DummyFile;
+use PHP_CodeSniffer\Ruleset;
+use PHP_CodeSniffer\Tests\ConfigDouble;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Miscellaneous tests for tab replacement.
+ *
+ * @covers PHP_CodeSniffer\Tokenizers\Tokenizer::replaceTabsInToken
+ */
+final class ReplaceTabsInTokenMiscTest extends TestCase
+{
+
+
+    /**
+     * Test that when no tab width is set or passed, the tab width will be set to 1.
+     *
+     * @return void
+     */
+    public function testTabWidthNotSet()
+    {
+        $config  = new ConfigDouble();
+        $ruleset = new Ruleset($config);
+
+        $content   = <<<EOD
+<?php
+		echo 'foo';
+EOD;
+        $phpcsFile = new DummyFile($content, $ruleset, $config);
+        $phpcsFile->parse();
+
+        $tokens = $phpcsFile->getTokens();
+        $target = $phpcsFile->findNext(T_WHITESPACE, 0);
+
+        // Verify initial state.
+        $this->assertTrue(is_int($target), 'Target token was not found');
+        $this->assertSame('		', $tokens[$target]['content'], 'Content after initial parsing does not contain tabs');
+        $this->assertSame(2, $tokens[$target]['length'], 'Length after initial parsing is not as expected');
+        $this->assertArrayNotHasKey('orig_content', $tokens[$target], "Key 'orig_content' found in the initial token array.");
+
+        $phpcsFile->tokenizer->replaceTabsInToken($tokens[$target]);
+
+        // Verify tab replacement.
+        $this->assertSame('  ', $tokens[$target]['content'], 'Content after tab replacement is not as expected');
+        $this->assertSame(2, $tokens[$target]['length'], 'Length after tab replacement is not as expected');
+        $this->assertArrayHasKey('orig_content', $tokens[$target], "Key 'orig_content' not found in the token array.");
+
+    }//end testTabWidthNotSet()
+
+
+    /**
+     * Test that the length calculation handles text in non-ascii encodings correctly.
+     *
+     * @requires extension iconv
+     *
+     * @return void
+     */
+    public function testLengthSettingRespectsEncoding()
+    {
+        $config           = new ConfigDouble();
+        $config->tabWidth = 4;
+        $ruleset          = new Ruleset($config);
+
+        $content   = <<<EOD
+<?php
+echo 'пасха		пасха';
+EOD;
+        $phpcsFile = new DummyFile($content, $ruleset, $config);
+        $phpcsFile->parse();
+
+        $tokens = $phpcsFile->getTokens();
+        $target = $phpcsFile->findNext(T_CONSTANT_ENCAPSED_STRING, 0);
+
+        $this->assertTrue(is_int($target), 'Target token was not found');
+        $this->assertSame("'пасха     пасха'", $tokens[$target]['content'], 'Content is not as expected');
+        $this->assertSame(17, $tokens[$target]['length'], 'Length is not as expected');
+        $this->assertArrayHasKey('orig_content', $tokens[$target], "Key 'orig_content' not found in the token array.");
+        $this->assertSame("'пасха		пасха'", $tokens[$target]['orig_content'], 'Orig_content is not as expected');
+
+    }//end testLengthSettingRespectsEncoding()
+
+
+    /**
+     * Test that the length calculation falls back to byte length if iconv detects an illegal character.
+     *
+     * @requires extension iconv
+     *
+     * @return void
+     */
+    public function testLengthSettingFallsBackToBytesWhenTextContainsIllegalChars()
+    {
+        $config           = new ConfigDouble();
+        $config->tabWidth = 4;
+        $ruleset          = new Ruleset($config);
+
+        $content   = <<<EOD
+<?php
+echo "aa\xC3\xC3	\xC3\xB8aa";
+EOD;
+        $phpcsFile = new DummyFile($content, $ruleset, $config);
+        $phpcsFile->parse();
+
+        $tokens = $phpcsFile->getTokens();
+        $target = $phpcsFile->findNext(T_CONSTANT_ENCAPSED_STRING, 0);
+
+        $this->assertTrue(is_int($target), 'Target token was not found');
+        $this->assertSame(11, $tokens[$target]['length'], 'Length is not as expected');
+        $this->assertArrayHasKey('orig_content', $tokens[$target], "Key 'orig_content' not found in the token array.");
+
+    }//end testLengthSettingFallsBackToBytesWhenTextContainsIllegalChars()
+
+
+}//end class
diff --git a/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTabWidth1Test.php b/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTabWidth1Test.php
new file mode 100644
index 0000000000..2962153454
--- /dev/null
+++ b/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTabWidth1Test.php
@@ -0,0 +1,111 @@
+<?php
+/**
+ * Tests the tab replacement logic.
+ *
+ * @author    Juliette Reinders Folmer <phpcs_nospam@adviesenzo.nl>
+ * @copyright 2024 PHPCSStandards and contributors
+ * @license   https://github.com/PHPCSStandards/PHP_CodeSniffer/blob/master/licence.txt BSD Licence
+ */
+
+namespace PHP_CodeSniffer\Tests\Core\Tokenizers\Tokenizer;
+
+/**
+ * Tab replacement test using tab width 1.
+ *
+ * @covers PHP_CodeSniffer\Tokenizers\Tokenizer::replaceTabsInToken
+ */
+final class ReplaceTabsInTokenTabWidth1Test extends ReplaceTabsInTokenTestCase
+{
+
+    /**
+     * The tab width setting to use when tokenizing the file.
+     *
+     * @var integer
+     */
+    protected $tabWidth = 1;
+
+
+    /**
+     * Data provider helper.
+     *
+     * @see ReplaceTabsInTokenTestCase::dataTabReplacement()
+     *
+     * @return array<string, array<string, int|string>>
+     */
+    public static function getTabReplacementExpected()
+    {
+        return [
+            'Tab indentation'                                                      => [
+                'length'       => 2,
+                'content'      => '  ',
+                'orig_content' => '		',
+            ],
+            'Mixed tab/space indentation'                                          => [
+                'length'       => 3,
+                'content'      => '   ',
+                'orig_content' => '	  ',
+            ],
+            'Inline: single tab in text string'                                    => [
+                'length'       => 15,
+                'content'      => "'tab separated'",
+                'orig_content' => "'tab	separated'",
+            ],
+            'Inline: single tab between each word in text string'                  => [
+                'length'       => 24,
+                'content'      => '"tab $between each word"',
+                'orig_content' => '"tab	$between	each	word"',
+            ],
+            'Inline: multiple tabs in heredoc'                                     => [
+                'length'       => 15,
+                'content'      => 'tab   separated
+',
+                'orig_content' => 'tab			separated
+',
+            ],
+            'Inline: multiple tabs between each word in nowdoc'                    => [
+                'length'       => 27,
+                'content'      => 'tab  between    each   word
+',
+                'orig_content' => 'tab		between				each			word
+',
+            ],
+            'Inline: mixed spaces/tabs in text string'                             => [
+                'length'       => 20,
+                'content'      => "'tab      separated'",
+                'orig_content' => "'tab 	  		separated'",
+            ],
+            'Inline: mixed spaces/tabs between each word in text string'           => [
+                'length'       => 31,
+                'content'      => '"tab  $between   each     word"',
+                'orig_content' => '"tab	 $between  	each	   	word"',
+            ],
+            'Inline: tab becomes single space in comment (with tabwidth 4)'        => [
+                'length'       => 50,
+                'content'      => '// -123 With tabwidth 4, the tab size should be 1.
+',
+                'orig_content' => '// -123	With tabwidth 4, the tab size should be 1.
+',
+            ],
+            'Inline: tab becomes 2 spaces in comment (with tabwidth 4)'            => [
+                'length'       => 52,
+                'content'      => '/* -12 With tabwidth 4, the tab size should be 2. */',
+                'orig_content' => '/* -12	With tabwidth 4, the tab size should be 2. */',
+            ],
+            'Inline: tab becomes 3 spaces in doc comment string (with tabwidth 4)' => [
+                'length'       => 45,
+                'content'      => '-1 With tabwidth 4, the tab size should be 3.',
+                'orig_content' => '-1	With tabwidth 4, the tab size should be 3.',
+            ],
+            'Inline: tab becomes 4 spaces in comment (with tabwidth 4)'            => [
+                'length'       => 47,
+                'content'      => '// - With tabwidth 4, the tab size should be 4.
+',
+                'orig_content' => '// -	With tabwidth 4, the tab size should be 4.
+',
+            ],
+        ];
+
+    }//end getTabReplacementExpected()
+
+
+}//end class
diff --git a/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTabWidth2Test.php b/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTabWidth2Test.php
new file mode 100644
index 0000000000..92de221d89
--- /dev/null
+++ b/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTabWidth2Test.php
@@ -0,0 +1,111 @@
+<?php
+/**
+ * Tests the tab replacement logic.
+ *
+ * @author    Juliette Reinders Folmer <phpcs_nospam@adviesenzo.nl>
+ * @copyright 2024 PHPCSStandards and contributors
+ * @license   https://github.com/PHPCSStandards/PHP_CodeSniffer/blob/master/licence.txt BSD Licence
+ */
+
+namespace PHP_CodeSniffer\Tests\Core\Tokenizers\Tokenizer;
+
+/**
+ * Tab replacement test using tab width 2.
+ *
+ * @covers PHP_CodeSniffer\Tokenizers\Tokenizer::replaceTabsInToken
+ */
+final class ReplaceTabsInTokenTabWidth2Test extends ReplaceTabsInTokenTestCase
+{
+
+    /**
+     * The tab width setting to use when tokenizing the file.
+     *
+     * @var integer
+     */
+    protected $tabWidth = 2;
+
+
+    /**
+     * Data provider helper.
+     *
+     * @see ReplaceTabsInTokenTestCase::dataTabReplacement()
+     *
+     * @return array<string, array<string, int|string>>
+     */
+    public static function getTabReplacementExpected()
+    {
+        return [
+            'Tab indentation'                                                      => [
+                'length'       => 4,
+                'content'      => '    ',
+                'orig_content' => '		',
+            ],
+            'Mixed tab/space indentation'                                          => [
+                'length'       => 4,
+                'content'      => '    ',
+                'orig_content' => '	  ',
+            ],
+            'Inline: single tab in text string'                                    => [
+                'length'       => 15,
+                'content'      => "'tab separated'",
+                'orig_content' => "'tab	separated'",
+            ],
+            'Inline: single tab between each word in text string'                  => [
+                'length'       => 26,
+                'content'      => '"tab $between  each  word"',
+                'orig_content' => '"tab	$between	each	word"',
+            ],
+            'Inline: multiple tabs in heredoc'                                     => [
+                'length'       => 17,
+                'content'      => 'tab     separated
+',
+                'orig_content' => 'tab			separated
+',
+            ],
+            'Inline: multiple tabs between each word in nowdoc'                    => [
+                'length'       => 34,
+                'content'      => 'tab   between       each      word
+',
+                'orig_content' => 'tab		between				each			word
+',
+            ],
+            'Inline: mixed spaces/tabs in text string'                             => [
+                'length'       => 23,
+                'content'      => "'tab         separated'",
+                'orig_content' => "'tab 	  		separated'",
+            ],
+            'Inline: mixed spaces/tabs between each word in text string'           => [
+                'length'       => 32,
+                'content'      => '"tab  $between   each      word"',
+                'orig_content' => '"tab	 $between  	each	   	word"',
+            ],
+            'Inline: tab becomes single space in comment (with tabwidth 4)'        => [
+                'length'       => 50,
+                'content'      => '// -123 With tabwidth 4, the tab size should be 1.
+',
+                'orig_content' => '// -123	With tabwidth 4, the tab size should be 1.
+',
+            ],
+            'Inline: tab becomes 2 spaces in comment (with tabwidth 4)'            => [
+                'length'       => 53,
+                'content'      => '/* -12  With tabwidth 4, the tab size should be 2. */',
+                'orig_content' => '/* -12	With tabwidth 4, the tab size should be 2. */',
+            ],
+            'Inline: tab becomes 3 spaces in doc comment string (with tabwidth 4)' => [
+                'length'       => 45,
+                'content'      => '-1 With tabwidth 4, the tab size should be 3.',
+                'orig_content' => '-1	With tabwidth 4, the tab size should be 3.',
+            ],
+            'Inline: tab becomes 4 spaces in comment (with tabwidth 4)'            => [
+                'length'       => 48,
+                'content'      => '// -  With tabwidth 4, the tab size should be 4.
+',
+                'orig_content' => '// -	With tabwidth 4, the tab size should be 4.
+',
+            ],
+        ];
+
+    }//end getTabReplacementExpected()
+
+
+}//end class
diff --git a/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTabWidth4Test.php b/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTabWidth4Test.php
new file mode 100644
index 0000000000..5f74187989
--- /dev/null
+++ b/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTabWidth4Test.php
@@ -0,0 +1,111 @@
+<?php
+/**
+ * Tests the tab replacement logic.
+ *
+ * @author    Juliette Reinders Folmer <phpcs_nospam@adviesenzo.nl>
+ * @copyright 2024 PHPCSStandards and contributors
+ * @license   https://github.com/PHPCSStandards/PHP_CodeSniffer/blob/master/licence.txt BSD Licence
+ */
+
+namespace PHP_CodeSniffer\Tests\Core\Tokenizers\Tokenizer;
+
+/**
+ * Tab replacement test using tab width 4.
+ *
+ * @covers PHP_CodeSniffer\Tokenizers\Tokenizer::replaceTabsInToken
+ */
+final class ReplaceTabsInTokenTabWidth4Test extends ReplaceTabsInTokenTestCase
+{
+
+    /**
+     * The tab width setting to use when tokenizing the file.
+     *
+     * @var integer
+     */
+    protected $tabWidth = 4;
+
+
+    /**
+     * Data provider helper.
+     *
+     * @see ReplaceTabsInTokenTestCase::dataTabReplacement()
+     *
+     * @return array<string, array<string, int|string>>
+     */
+    public static function getTabReplacementExpected()
+    {
+        return [
+            'Tab indentation'                                                      => [
+                'length'       => 8,
+                'content'      => '        ',
+                'orig_content' => '		',
+            ],
+            'Mixed tab/space indentation'                                          => [
+                'length'       => 6,
+                'content'      => '      ',
+                'orig_content' => '	  ',
+            ],
+            'Inline: single tab in text string'                                    => [
+                'length'       => 17,
+                'content'      => "'tab   separated'",
+                'orig_content' => "'tab	separated'",
+            ],
+            'Inline: single tab between each word in text string'                  => [
+                'length'       => 32,
+                'content'      => '"tab   $between    each    word"',
+                'orig_content' => '"tab	$between	each	word"',
+            ],
+            'Inline: multiple tabs in heredoc'                                     => [
+                'length'       => 21,
+                'content'      => 'tab         separated
+',
+                'orig_content' => 'tab			separated
+',
+            ],
+            'Inline: multiple tabs between each word in nowdoc'                    => [
+                'length'       => 48,
+                'content'      => 'tab     between             each            word
+',
+                'orig_content' => 'tab		between				each			word
+',
+            ],
+            'Inline: mixed spaces/tabs in text string'                             => [
+                'length'       => 25,
+                'content'      => "'tab           separated'",
+                'orig_content' => "'tab 	  		separated'",
+            ],
+            'Inline: mixed spaces/tabs between each word in text string'           => [
+                'length'       => 36,
+                'content'      => '"tab    $between   each        word"',
+                'orig_content' => '"tab	 $between  	each	   	word"',
+            ],
+            'Inline: tab becomes single space in comment (with tabwidth 4)'        => [
+                'length'       => 50,
+                'content'      => '// -123 With tabwidth 4, the tab size should be 1.
+',
+                'orig_content' => '// -123	With tabwidth 4, the tab size should be 1.
+',
+            ],
+            'Inline: tab becomes 2 spaces in comment (with tabwidth 4)'            => [
+                'length'       => 53,
+                'content'      => '/* -12  With tabwidth 4, the tab size should be 2. */',
+                'orig_content' => '/* -12	With tabwidth 4, the tab size should be 2. */',
+            ],
+            'Inline: tab becomes 3 spaces in doc comment string (with tabwidth 4)' => [
+                'length'       => 47,
+                'content'      => '-1   With tabwidth 4, the tab size should be 3.',
+                'orig_content' => '-1	With tabwidth 4, the tab size should be 3.',
+            ],
+            'Inline: tab becomes 4 spaces in comment (with tabwidth 4)'            => [
+                'length'       => 50,
+                'content'      => '// -    With tabwidth 4, the tab size should be 4.
+',
+                'orig_content' => '// -	With tabwidth 4, the tab size should be 4.
+',
+            ],
+        ];
+
+    }//end getTabReplacementExpected()
+
+
+}//end class
diff --git a/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTabWidth5Test.php b/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTabWidth5Test.php
new file mode 100644
index 0000000000..361894fb94
--- /dev/null
+++ b/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTabWidth5Test.php
@@ -0,0 +1,111 @@
+<?php
+/**
+ * Tests the tab replacement logic.
+ *
+ * @author    Juliette Reinders Folmer <phpcs_nospam@adviesenzo.nl>
+ * @copyright 2024 PHPCSStandards and contributors
+ * @license   https://github.com/PHPCSStandards/PHP_CodeSniffer/blob/master/licence.txt BSD Licence
+ */
+
+namespace PHP_CodeSniffer\Tests\Core\Tokenizers\Tokenizer;
+
+/**
+ * Tab replacement test using tab width 5.
+ *
+ * @covers PHP_CodeSniffer\Tokenizers\Tokenizer::replaceTabsInToken
+ */
+final class ReplaceTabsInTokenTabWidth5Test extends ReplaceTabsInTokenTestCase
+{
+
+    /**
+     * The tab width setting to use when tokenizing the file.
+     *
+     * @var integer
+     */
+    protected $tabWidth = 5;
+
+
+    /**
+     * Data provider helper.
+     *
+     * @see ReplaceTabsInTokenTestCase::dataTabReplacement()
+     *
+     * @return array<string, array<string, int|string>>
+     */
+    public static function getTabReplacementExpected()
+    {
+        return [
+            'Tab indentation'                                                      => [
+                'length'       => 10,
+                'content'      => '          ',
+                'orig_content' => '		',
+            ],
+            'Mixed tab/space indentation'                                          => [
+                'length'       => 7,
+                'content'      => '       ',
+                'orig_content' => '	  ',
+            ],
+            'Inline: single tab in text string'                                    => [
+                'length'       => 15,
+                'content'      => "'tab separated'",
+                'orig_content' => "'tab	separated'",
+            ],
+            'Inline: single tab between each word in text string'                  => [
+                'length'       => 25,
+                'content'      => '"tab $between  each word"',
+                'orig_content' => '"tab	$between	each	word"',
+            ],
+            'Inline: multiple tabs in heredoc'                                     => [
+                'length'       => 24,
+                'content'      => 'tab            separated
+',
+                'orig_content' => 'tab			separated
+',
+            ],
+            'Inline: multiple tabs between each word in nowdoc'                    => [
+                'length'       => 54,
+                'content'      => 'tab       between                  each           word
+',
+                'orig_content' => 'tab		between				each			word
+',
+            ],
+            'Inline: mixed spaces/tabs in text string'                             => [
+                'length'       => 30,
+                'content'      => "'tab                separated'",
+                'orig_content' => "'tab 	  		separated'",
+            ],
+            'Inline: mixed spaces/tabs between each word in text string'           => [
+                'length'       => 35,
+                'content'      => '"tab  $between      each      word"',
+                'orig_content' => '"tab	 $between  	each	   	word"',
+            ],
+            'Inline: tab becomes single space in comment (with tabwidth 4)'        => [
+                'length'       => 52,
+                'content'      => '// -123   With tabwidth 4, the tab size should be 1.
+',
+                'orig_content' => '// -123	With tabwidth 4, the tab size should be 1.
+',
+            ],
+            'Inline: tab becomes 2 spaces in comment (with tabwidth 4)'            => [
+                'length'       => 55,
+                'content'      => '/* -12    With tabwidth 4, the tab size should be 2. */',
+                'orig_content' => '/* -12	With tabwidth 4, the tab size should be 2. */',
+            ],
+            'Inline: tab becomes 3 spaces in doc comment string (with tabwidth 4)' => [
+                'length'       => 49,
+                'content'      => '-1     With tabwidth 4, the tab size should be 3.',
+                'orig_content' => '-1	With tabwidth 4, the tab size should be 3.',
+            ],
+            'Inline: tab becomes 4 spaces in comment (with tabwidth 4)'            => [
+                'length'       => 47,
+                'content'      => '// - With tabwidth 4, the tab size should be 4.
+',
+                'orig_content' => '// -	With tabwidth 4, the tab size should be 4.
+',
+            ],
+        ];
+
+    }//end getTabReplacementExpected()
+
+
+}//end class
diff --git a/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTest.inc b/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTest.inc
new file mode 100644
index 0000000000..e6046500e5
--- /dev/null
+++ b/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTest.inc
@@ -0,0 +1,46 @@
+<?php
+
+/* testNoReplacementNeeded */
+    $a = 10; // Comment not containing any tabs.
+
+/* testTabIndentation */
+		echo $foo;
+
+/* testMixedIndentation */
+	  echo $foo;
+
+/* testInlineSingleTab */
+$a = 'tab	separated';
+
+/* testInlineSingleTabBetweenEachWord */
+$a = "tab	$between	each	word";
+
+/* testInlineMultiTab */
+$a = <<<EOD
+tab			separated
+EOD;
+
+/* testInlineMultipleTabsBetweenEachWord */
+$a = <<<'EOD'
+tab		between				each			word
+EOD;
+
+/* testInlineMixedSpacesTabs */
+$a = 'tab 	  		separated';
+
+/* testInlineMixedSpacesTabsBetweenEachWord */
+$a = "tab	 $between  	each	   	word";
+
+/* testInlineSize1 */
+// -123	With tabwidth 4, the tab size should be 1.
+
+/* testInlineSize2 */
+/* -12	With tabwidth 4, the tab size should be 2. */
+
+/* testInlineSize3 */
+/**
+ * -1	With tabwidth 4, the tab size should be 3.
+ */
+
+/* testInlineSize4 */
+// -	With tabwidth 4, the tab size should be 4.
diff --git a/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTestCase.php b/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTestCase.php
new file mode 100644
index 0000000000..93964e1607
--- /dev/null
+++ b/tests/Core/Tokenizers/Tokenizer/ReplaceTabsInTokenTestCase.php
@@ -0,0 +1,274 @@
+<?php
+/**
+ * Base class to test the tab replacement logic.
+ *
+ * @author    Juliette Reinders Folmer <phpcs_nospam@adviesenzo.nl>
+ * @copyright 2024 PHPCSStandards and contributors
+ * @license   https://github.com/PHPCSStandards/PHP_CodeSniffer/blob/master/licence.txt BSD Licence
+ */
+
+namespace PHP_CodeSniffer\Tests\Core\Tokenizers\Tokenizer;
+
+use Exception;
+use PHP_CodeSniffer\Tests\Core\Tokenizers\AbstractTokenizerTestCase;
+
+/**
+ * Tab replacement test case.
+ *
+ * @covers PHP_CodeSniffer\Tokenizers\Tokenizer::replaceTabsInToken
+ */
+abstract class ReplaceTabsInTokenTestCase extends AbstractTokenizerTestCase
+{
+
+    /**
+     * The name of the test case file used by this test.
+     *
+     * @var string
+     */
+    private static $caseFileName;
+
+
+    /**
+     * Make a copy the test case file we want to use for this test (as the file will be used by multiple tests).
+     *
+     * @beforeClass
+     *
+     * @return void
+     *
+     * @throws \Exception In case the base test case file would not be available.
+     */
+    public static function copyCaseFile()
+    {
+        $relativeCN         = str_replace(__NAMESPACE__.'\\', '', get_called_class());
+        self::$caseFileName = __DIR__.DIRECTORY_SEPARATOR.$relativeCN.'.inc';
+
+        $baseFileName = realpath(__DIR__.'/ReplaceTabsInTokenTest.inc');
+        if (is_string($baseFileName) === false) {
+            throw new Exception('Base test case file "ReplaceTabsInTokenTest.inc" not found');
+        }
+
+        if (copy($baseFileName, self::$caseFileName) === false) {
+            throw new Exception(sprintf('Failed to copy test case file "ReplaceTabsInTokenTest.inc" to %s', self::$caseFileName));
+        }
+
+    }//end copyCaseFile()
+
+
+    /**
+     * Delete the copied test case file after use.
+     *
+     * @afterClass
+     *
+     * @return void
+     */
+    public static function deleteCaseFile()
+    {
+        @unlink(self::$caseFileName);
+
+    }//end deleteCaseFile()
+
+
+    /**
+     * Verify that if a token not containing tabs would be passed to the replaceTabsInToken() method,
+     * yes, the `orig_content` key is added, but no changes are made to the token `content` or `length` values.
+     *
+     * @param string                         $testMarker The comment prefacing the target token.
+     * @param int|string                     $testTarget Token code to look for.
+     * @param array<string, int|string|null> $expected   Expectations for the token array.
+     * @param int                            $offset     Optional. Offset from the target token to get to the _real_ target.
+     *                                                   This is specifically needed to target indentation whitespace.
+     *
+     * @dataProvider dataNoReplacementsAreMadeWhenNoTabsAreFound
+     *
+     * @return void
+     */
+    public function testNoReplacementsAreMadeWhenNoTabsAreFound($testMarker, $testTarget, $expected, $offset=0)
+    {
+        $tokens  = $this->phpcsFile->getTokens();
+        $target  = $this->getTargetToken($testMarker, $testTarget);
+        $target += $offset;
+
+        foreach ($expected as $key => $value) {
+            if ($key === 'orig_content' && $value === null) {
+                $this->assertArrayNotHasKey($key, $tokens[$target], "Unexpected 'orig_content' key found in the token array.");
+                continue;
+            }
+
+            $this->assertArrayHasKey($key, $tokens[$target], "Key $key not found in the token array.");
+            $this->assertSame($value, $tokens[$target][$key], "Value for key $key does not match expectation.");
+        }
+
+    }//end testNoReplacementsAreMadeWhenNoTabsAreFound()
+
+
+    /**
+     * Data provider.
+     *
+     * @see testNoReplacementsAreMadeWhenNoTabsAreFound()
+     *
+     * @return array<string, array<string, int|string|array<string, int|string|null>>>
+     */
+    public static function dataNoReplacementsAreMadeWhenNoTabsAreFound()
+    {
+        return [
+            'Indentation whitespace, only spaces'      => [
+                'testMarker' => '/* testNoReplacementNeeded */',
+                'testTarget' => T_WHITESPACE,
+                'expected'   => [
+                    'length'       => 4,
+                    'content'      => '    ',
+                    'orig_content' => null,
+                ],
+                'offset'     => 1,
+            ],
+            'Trailing comment not containing any tabs' => [
+                'testMarker' => '/* testNoReplacementNeeded */',
+                'testTarget' => T_COMMENT,
+                'expected'   => [
+                    'length'       => 35,
+                    'content'      => '// Comment not containing any tabs.
+',
+                    'orig_content' => null,
+                ],
+            ],
+        ];
+
+    }//end dataNoReplacementsAreMadeWhenNoTabsAreFound()
+
+
+    /**
+     * Test tab replacement in tokens.
+     *
+     * @param string                         $testMarker The comment prefacing the target token.
+     * @param int|string                     $testTarget Token code to look for.
+     * @param array<string, int|string|null> $expected   Expectations for the token array.
+     * @param int                            $offset     Optional. Offset from the target token to get to the _real_ target.
+     *                                                   This is specifically needed to target indentation whitespace.
+     *
+     * @dataProvider dataTabReplacement
+     *
+     * @return void
+     */
+    public function testTabReplacement($testMarker, $testTarget, $expected, $offset=0)
+    {
+        $tokens  = $this->phpcsFile->getTokens();
+        $target  = $this->getTargetToken($testMarker, $testTarget);
+        $target += $offset;
+
+        foreach ($expected as $key => $value) {
+            if ($key === 'orig_content' && $value === null) {
+                $this->assertArrayNotHasKey($key, $tokens[$target], "Unexpected 'orig_content' key found in the token array.");
+                continue;
+            }
+
+            $this->assertArrayHasKey($key, $tokens[$target], "Key $key not found in the token array.");
+            $this->assertSame($value, $tokens[$target][$key], "Value for key $key does not match expectation.");
+        }
+
+    }//end testTabReplacement()
+
+
+    /**
+     * Data provider.
+     *
+     * @see testTabReplacement()
+     *
+     * @return array<string, array<string, int|string|array<string, int|string>>>
+     *
+     * @throws \Exception When the getTabReplacementExpected() method doesn't provide data in the correct format.
+     */
+    public static function dataTabReplacement()
+    {
+        $data = [
+            'Tab indentation'                                                      => [
+                'testMarker' => '/* testTabIndentation */',
+                'testTarget' => T_WHITESPACE,
+            ],
+            'Mixed tab/space indentation'                                          => [
+                'testMarker' => '/* testMixedIndentation */',
+                'testTarget' => T_WHITESPACE,
+            ],
+            'Inline: single tab in text string'                                    => [
+                'testMarker' => '/* testInlineSingleTab */',
+                'testTarget' => T_CONSTANT_ENCAPSED_STRING,
+            ],
+            'Inline: single tab between each word in text string'                  => [
+                'testMarker' => '/* testInlineSingleTabBetweenEachWord */',
+                'testTarget' => T_DOUBLE_QUOTED_STRING,
+            ],
+            'Inline: multiple tabs in heredoc'                                     => [
+                'testMarker' => '/* testInlineMultiTab */',
+                'testTarget' => T_HEREDOC,
+            ],
+            'Inline: multiple tabs between each word in nowdoc'                    => [
+                'testMarker' => '/* testInlineMultipleTabsBetweenEachWord */',
+                'testTarget' => T_NOWDOC,
+            ],
+            'Inline: mixed spaces/tabs in text string'                             => [
+                'testMarker' => '/* testInlineMixedSpacesTabs */',
+                'testTarget' => T_CONSTANT_ENCAPSED_STRING,
+            ],
+            'Inline: mixed spaces/tabs between each word in text string'           => [
+                'testMarker' => '/* testInlineMixedSpacesTabsBetweenEachWord */',
+                'testTarget' => T_DOUBLE_QUOTED_STRING,
+            ],
+            'Inline: tab becomes single space in comment (with tabwidth 4)'        => [
+                'testMarker' => '/* testInlineSize1 */',
+                'testTarget' => T_COMMENT,
+            ],
+            'Inline: tab becomes 2 spaces in comment (with tabwidth 4)'            => [
+                'testMarker' => '/* testInlineSize2 */',
+                'testTarget' => T_COMMENT,
+            ],
+            'Inline: tab becomes 3 spaces in doc comment string (with tabwidth 4)' => [
+                'testMarker' => '/* testInlineSize3 */',
+                'testTarget' => T_DOC_COMMENT_STRING,
+            ],
+            'Inline: tab becomes 4 spaces in comment (with tabwidth 4)'            => [
+                'testMarker' => '/* testInlineSize4 */',
+                'testTarget' => T_COMMENT,
+            ],
+        ];
+
+        $expectations = static::getTabReplacementExpected();
+
+        foreach ($data as $key => $value) {
+            if (isset($expectations[$key]) === false || is_array($expectations[$key]) === false) {
+                throw new Exception(
+                    sprintf('Invalid getTabReplacementExpected() method. Missing expectation array for the "%s" test case', $key)
+                );
+            }
+
+            if (isset($expectations[$key]['length'], $expectations[$key]['content']) === false
+                || array_key_exists('orig_content', $expectations[$key]) === false
+            ) {
+                throw new Exception(
+                    sprintf('Invalid expectation array for the "%s" test case. The array must contain the "length", "content" and "orig_content" keys', $key)
+                );
+            }
+
+            $data[$key]['expected'] = $expectations[$key];
+        }
+
+        // Set offset for test cases targetting whitespace.
+        $data['Tab indentation']['offset'] = 1;
+        $data['Mixed tab/space indentation']['offset'] = 1;
+
+        return $data;
+
+    }//end dataTabReplacement()
+
+
+    /**
+     * Data provider helper.
+     *
+     * Should be declared in child classes to set the expectations for the token array.
+     *
+     * @see dataTabReplacement()
+     *
+     * @return array<string, array<string, int|string|null>>
+     */
+    abstract public static function getTabReplacementExpected();
+
+
+}//end class