Add major GR banks to el_GR bank provider

faker/providers/bank/el_GR/__init__.py

@@ -6,3 +6,23 @@ class Provider(BankProvider):
 
     bban_format = "#######################"
     country_code = "GR"
+
+    # Major GR banks (with a head office in Greece)
+    # Source:
+    # - https://www.bankofgreece.gr/en/main-tasks/supervision/supervised-institutions
+    # Last verified: January 2026
+    banks = (
+        "Aegean Baltic Bank",
+        "Alpha Bank",        
+        "Credia Bank",
+        "Eurobank",
+        "Optima Bank",
+        "SNAPPI",
+        "Vivabank",   
+        "Εθνική Τράπεζα",
+        "Συνεταιριστική Τράπεζα Θεσσαλίας",
+        "Συνεταιριστική Τράπεζα Καρδίτσας",
+        "Συνεταιριστική Τράπεζα Χανίων",
+        "Τράπεζα Ηπείρου",
+        "Τράπεζα Πειραιώς",
+    )

tests/providers/test_bank.py

@@ -440,6 +440,11 @@ def test_iban(self, faker, num_samples):
 class TestElGr:
     """Test el_GR bank provider"""
 
+    def test_bank(self, faker, num_samples):
+        for _ in range(num_samples):
+            bank = faker.bank()
+            assert bank in ElGrBankProvider.banks
+
     def test_bban(self, faker, num_samples):
         for _ in range(num_samples):
             assert re.fullmatch(r"\d{23}", faker.bban())