diff --git a/app/code/core/Mage/Admin/Model/User.php b/app/code/core/Mage/Admin/Model/User.php
index 710683dfdda..edb9513824f 100644
--- a/app/code/core/Mage/Admin/Model/User.php
+++ b/app/code/core/Mage/Admin/Model/User.php
@@ -130,9 +130,9 @@ protected function _construct()
     protected function _beforeSave()
     {
         $data = [
-            'firstname' => $this->getFirstname(),
-            'lastname'  => $this->getLastname(),
-            'email'     => $this->getEmail(),
+            'firstname' => trim((string) $this->getFirstname()),
+            'lastname'  => trim((string) $this->getLastname()),
+            'email'     => trim((string) $this->getEmail()),
             'modified'  => $this->_getDateNow(),
             'extra'     => serialize($this->getExtra()),
         ];
@@ -142,7 +142,7 @@ protected function _beforeSave()
         }
 
         if ($this->getUsername()) {
-            $data['username'] = $this->getUsername();
+            $data['username'] = trim((string) $this->getUsername());
         }
 
         if ($this->getNewPassword()) {
diff --git a/app/code/core/Mage/Core/Controller/Request/Http.php b/app/code/core/Mage/Core/Controller/Request/Http.php
index cd82106eda9..ca0cd5f1684 100644
--- a/app/code/core/Mage/Core/Controller/Request/Http.php
+++ b/app/code/core/Mage/Core/Controller/Request/Http.php
@@ -584,4 +584,30 @@ public function getInternallyForwarded()
     {
         return $this->_internallyForwarded;
     }
+
+    /**
+     * Retrieve a parameter from request (GET/POST) and trim whitespace for string and array values.
+     *
+     * @param string $key
+     * @param mixed $default
+     * @return mixed
+     */
+    public function getParam($key, $default = null)
+    {
+        // Get the parameter value from parent (Zend_Controller_Request_Http)
+        $value = parent::getParam($key, $default);
+
+        // Trim whitespace for string values
+        if (is_string($value)) {
+            $value = trim($value);
+        }
+
+        // For array values, trim each string element
+        if (is_array($value)) {
+            $value = array_map(function ($v) {
+                return is_string($v) ? trim($v) : $v;
+            }, $value);
+        }
+        return $value;
+    }
 }
diff --git a/app/code/core/Mage/Sales/Model/Order/Address.php b/app/code/core/Mage/Sales/Model/Order/Address.php
index cc22549276a..6373cad4cc8 100644
--- a/app/code/core/Mage/Sales/Model/Order/Address.php
+++ b/app/code/core/Mage/Sales/Model/Order/Address.php
@@ -122,11 +122,19 @@ public function getOrder()
 
     /**
      * Before object save manipulations
+     * Trim whitespace for all string data to prevent unwanted spaces on save
      *
      * @return $this
      */
     protected function _beforeSave()
     {
+        // Trim all string fields before saving (for clean data storage)
+        foreach ($this->getData() as $key => $value) {
+            if (is_string($value)) {
+                $this->setData($key, trim($value));
+            }
+        }
+
         parent::_beforeSave();
 
         if (!$this->getParentId() && $this->getOrder()) {
diff --git a/app/code/core/Mage/Tag/Model/Resource/Tag.php b/app/code/core/Mage/Tag/Model/Resource/Tag.php
index 7cff76d130c..5c31e2791f3 100644
--- a/app/code/core/Mage/Tag/Model/Resource/Tag.php
+++ b/app/code/core/Mage/Tag/Model/Resource/Tag.php
@@ -67,6 +67,9 @@ public function loadByName($model, $name)
      */
     protected function _beforeSave(Mage_Core_Model_Abstract $object)
     {
+        // Trim whitespace for Tag name
+        $object->setName(trim($object->getName()));
+
         if (!$object->getId() && $object->getStatus() == $object->getApprovedStatus()) {
             $searchTag = new Varien_Object();
             $this->loadByName($searchTag, $object->getName());
diff --git a/app/code/core/Mage/Tax/Model/Calculation/Rate.php b/app/code/core/Mage/Tax/Model/Calculation/Rate.php
index bf63df54929..dd394a6adf9 100644
--- a/app/code/core/Mage/Tax/Model/Calculation/Rate.php
+++ b/app/code/core/Mage/Tax/Model/Calculation/Rate.php
@@ -69,6 +69,15 @@ protected function _construct()
      */
     protected function _beforeSave()
     {
+        // Trim whitespace for all relevant fields before validation and save
+        $this->setCode(trim((string) $this->getCode()));
+        $this->setTaxCountryId(trim((string) $this->getTaxCountryId()));
+        $this->setTaxRegionId(trim((string) $this->getTaxRegionId()));
+        $this->setTaxPostcode(trim((string) $this->getTaxPostcode()));
+        $this->setRate(trim((string) $this->getRate()));
+        $this->setZipFrom(trim((string) $this->getZipFrom()));
+        $this->setZipTo(trim((string) $this->getZipTo()));
+
         if ($this->getCode() === '' || $this->getTaxCountryId() === '' || $this->getRate() === ''
             || $this->getZipIsRange() && ($this->getZipFrom() === '' || $this->getZipTo() === '')
         ) {