diff --git a/src/alpine_bits_python/api.py b/src/alpine_bits_python/api.py
index 4f84fce..b9d409c 100644
--- a/src/alpine_bits_python/api.py
+++ b/src/alpine_bits_python/api.py
@@ -70,6 +70,86 @@ security_bearer = HTTPBearer()
 # Constants for token sanitization
 TOKEN_LOG_LENGTH = 10
 
+# Country name to ISO 3166-1 alpha-2 code mapping
+COUNTRY_NAME_TO_CODE = {
+    # English names
+    "germany": "DE",
+    "italy": "IT",
+    "austria": "AT",
+    "switzerland": "CH",
+    "france": "FR",
+    "netherlands": "NL",
+    "belgium": "BE",
+    "spain": "ES",
+    "portugal": "PT",
+    "united kingdom": "GB",
+    "uk": "GB",
+    "czech republic": "CZ",
+    "poland": "PL",
+    "hungary": "HU",
+    "croatia": "HR",
+    "slovenia": "SI",
+    # German names
+    "deutschland": "DE",
+    "italien": "IT",
+    "österreich": "AT",
+    "schweiz": "CH",
+    "frankreich": "FR",
+    "niederlande": "NL",
+    "belgien": "BE",
+    "spanien": "ES",
+    "vereinigtes königreich": "GB",
+    "tschechien": "CZ",
+    "polen": "PL",
+    "ungarn": "HU",
+    "kroatien": "HR",
+    "slowenien": "SI",
+    # Italian names
+    "germania": "DE",
+    "italia": "IT",
+    "svizzera": "CH",
+    "francia": "FR",
+    "paesi bassi": "NL",
+    "belgio": "BE",
+    "spagna": "ES",
+    "portogallo": "PT",
+    "regno unito": "GB",
+    "repubblica ceca": "CZ",
+    "polonia": "PL",
+    "ungheria": "HU",
+    "croazia": "HR",
+}
+
+
+def normalize_country_input(country_input: str | None) -> str | None:
+    """Normalize country input to ISO 3166-1 alpha-2 code.
+
+    Handles:
+    - Country names in English, German, and Italian
+    - Already valid 2-letter codes (case-insensitive)
+    - None/empty values
+
+    Args:
+        country_input: Country name or code (case-insensitive)
+
+    Returns:
+        2-letter ISO country code (uppercase) or None if input is None/empty
+
+    """
+    if not country_input:
+        return None
+
+    country_input = country_input.strip()
+
+    # If already 2 letters, assume it's a country code (ISO 3166-1 alpha-2)
+    iso_country_code_length = 2
+    if len(country_input) == iso_country_code_length and country_input.isalpha():
+        return country_input.upper()
+
+    # Try to match as country name (case-insensitive)
+    country_lower = country_input.lower()
+    return COUNTRY_NAME_TO_CODE.get(country_lower, country_input)
+
 
 # Pydantic models for language detection
 class LanguageDetectionRequest(BaseModel):
@@ -738,6 +818,9 @@ async def process_generic_webhook_submission(
     city = form_data.get("stadt", "")
     country = form_data.get("land", "")
 
+    # Normalize country input (convert names to codes, handle case)
+    country = normalize_country_input(country)
+
     # Parse dates - handle DD.MM.YYYY format
     start_date_str = form_data.get("anreise")
     end_date_str = form_data.get("abreise")
diff --git a/src/alpine_bits_python/customer_service.py b/src/alpine_bits_python/customer_service.py
index 03243b7..7614e75 100644
--- a/src/alpine_bits_python/customer_service.py
+++ b/src/alpine_bits_python/customer_service.py
@@ -1,12 +1,16 @@
 """Customer service layer for handling customer and hashed customer operations."""
 
 from datetime import UTC, datetime
-from typing import Optional
 
+from pydantic import ValidationError
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from .db import Customer, HashedCustomer
+from .logging_config import get_logger
+from .schemas import CustomerData
+
+_LOGGER = get_logger(__name__)
 
 
 class CustomerService:
@@ -27,9 +31,27 @@ class CustomerService:
 
         Returns:
             The created Customer instance (with hashed_version relationship populated)
+
+        Raises:
+            ValidationError: If customer_data fails validation
+                (e.g., invalid country code)
+
         """
-        # Create the customer
-        customer = Customer(**customer_data)
+        # Validate customer data through Pydantic model
+        validated_data = CustomerData(**customer_data)
+
+        # Create the customer with validated data
+        # Exclude 'phone_numbers' as Customer model uses 'phone' field
+        customer = Customer(
+            **validated_data.model_dump(exclude_none=True, exclude={"phone_numbers"})
+        )
+
+        # Set fields not in CustomerData model separately
+        if "contact_id" in customer_data:
+            customer.contact_id = customer_data["contact_id"]
+        if "phone" in customer_data:
+            customer.phone = customer_data["phone"]
+
         self.session.add(customer)
         await self.session.flush()  # Flush to get the customer.id
 
@@ -43,9 +65,7 @@ class CustomerService:
 
         return customer
 
-    async def update_customer(
-        self, customer: Customer, update_data: dict
-    ) -> Customer:
+    async def update_customer(self, customer: Customer, update_data: dict) -> Customer:
         """Update an existing customer and sync its hashed version.
 
         Args:
@@ -54,17 +74,62 @@ class CustomerService:
 
         Returns:
             The updated Customer instance
+
+        Raises:
+            ValidationError: If update_data fails validation
+                (e.g., invalid country code)
+
         """
-        # Update customer fields
-        for key, value in update_data.items():
+        # Validate update data through Pydantic model
+        # We need to merge with existing data for validation
+        existing_data = {
+            "given_name": customer.given_name,
+            "surname": customer.surname,
+            "name_prefix": customer.name_prefix,
+            "email_address": customer.email_address,
+            "phone": customer.phone,
+            "email_newsletter": customer.email_newsletter,
+            "address_line": customer.address_line,
+            "city_name": customer.city_name,
+            "postal_code": customer.postal_code,
+            "country_code": customer.country_code,
+            "gender": customer.gender,
+            "birth_date": customer.birth_date,
+            "language": customer.language,
+            "address_catalog": customer.address_catalog,
+            "name_title": customer.name_title,
+        }
+        # Merge update_data into existing_data (only CustomerData fields)
+        # Filter to include only fields that exist in CustomerData model
+        customer_data_fields = set(CustomerData.model_fields.keys())
+        # Include 'phone' field (maps to CustomerData)
+        existing_data.update(
+            {
+                k: v
+                for k, v in update_data.items()
+                if k in customer_data_fields or k == "phone"
+            }
+        )
+
+        # Validate merged data
+        validated_data = CustomerData(**existing_data)
+
+        # Update customer fields with validated data
+        # Exclude 'phone_numbers' as Customer model uses 'phone' field
+        # Note: We don't use exclude_none=True to allow setting fields to None
+        for key, value in validated_data.model_dump(exclude={"phone_numbers"}).items():
             if hasattr(customer, key):
                 setattr(customer, key, value)
 
+        # Update fields not in CustomerData model separately
+        if "contact_id" in update_data:
+            customer.contact_id = update_data["contact_id"]
+        if "phone" in update_data:
+            customer.phone = update_data["phone"]
+
         # Update or create hashed version
         result = await self.session.execute(
-            select(HashedCustomer).where(
-                HashedCustomer.customer_id == customer.id
-            )
+            select(HashedCustomer).where(HashedCustomer.customer_id == customer.id)
         )
         hashed_customer = result.scalar_one_or_none()
 
@@ -91,9 +156,7 @@ class CustomerService:
 
         return customer
 
-    async def get_customer_by_contact_id(
-        self, contact_id: str
-    ) -> Optional[Customer]:
+    async def get_customer_by_contact_id(self, contact_id: str) -> Customer | None:
         """Get a customer by contact_id.
 
         Args:
@@ -101,6 +164,7 @@ class CustomerService:
 
         Returns:
             Customer instance if found, None otherwise
+
         """
         result = await self.session.execute(
             select(Customer).where(Customer.contact_id == contact_id)
@@ -118,6 +182,7 @@ class CustomerService:
 
         Returns:
             Existing or newly created Customer instance
+
         """
         contact_id = customer_data.get("contact_id")
 
@@ -130,9 +195,7 @@ class CustomerService:
         # Create new customer (either no contact_id or customer doesn't exist)
         return await self.create_customer(customer_data)
 
-    async def get_hashed_customer(
-        self, customer_id: int
-    ) -> Optional[HashedCustomer]:
+    async def get_hashed_customer(self, customer_id: int) -> HashedCustomer | None:
         """Get the hashed version of a customer.
 
         Args:
@@ -140,11 +203,10 @@ class CustomerService:
 
         Returns:
             HashedCustomer instance if found, None otherwise
+
         """
         result = await self.session.execute(
-            select(HashedCustomer).where(
-                HashedCustomer.customer_id == customer_id
-            )
+            select(HashedCustomer).where(HashedCustomer.customer_id == customer_id)
         )
         return result.scalar_one_or_none()
 
@@ -154,25 +216,79 @@ class CustomerService:
         This is useful for backfilling hashed data for customers created
         before the hashing system was implemented.
 
+        Also validates and sanitizes customer data (e.g., normalizes country
+        codes to uppercase). Customers with invalid data that cannot be fixed
+        will be skipped and logged.
+
         Returns:
             Number of customers that were hashed
+
         """
         # Get all customers
         result = await self.session.execute(select(Customer))
         customers = result.scalars().all()
 
         hashed_count = 0
+        skipped_count = 0
+
         for customer in customers:
             # Check if this customer already has a hashed version
             existing_hashed = await self.get_hashed_customer(customer.id)
             if not existing_hashed:
-                # Create hashed version
-                hashed_customer = customer.create_hashed_customer()
-                hashed_customer.created_at = datetime.now(UTC)
-                self.session.add(hashed_customer)
-                hashed_count += 1
+                # Validate and sanitize customer data before hashing
+                customer_dict = {
+                    "given_name": customer.given_name,
+                    "surname": customer.surname,
+                    "name_prefix": customer.name_prefix,
+                    "email_address": customer.email_address,
+                    "phone": customer.phone,
+                    "email_newsletter": customer.email_newsletter,
+                    "address_line": customer.address_line,
+                    "city_name": customer.city_name,
+                    "postal_code": customer.postal_code,
+                    "country_code": customer.country_code,
+                    "gender": customer.gender,
+                    "birth_date": customer.birth_date,
+                    "language": customer.language,
+                    "address_catalog": customer.address_catalog,
+                    "name_title": customer.name_title,
+                }
+
+                try:
+                    # Validate through Pydantic (normalizes country code)
+                    validated = CustomerData(**customer_dict)
+
+                    # Update customer with sanitized data
+                    # Exclude 'phone_numbers' as Customer model uses 'phone' field
+                    for key, value in validated.model_dump(
+                        exclude_none=True, exclude={"phone_numbers"}
+                    ).items():
+                        if hasattr(customer, key):
+                            setattr(customer, key, value)
+
+                    # Create hashed version with sanitized data
+                    hashed_customer = customer.create_hashed_customer()
+                    hashed_customer.created_at = datetime.now(UTC)
+                    self.session.add(hashed_customer)
+                    hashed_count += 1
+
+                except ValidationError as e:
+                    # Skip customers with invalid data and log
+                    skipped_count += 1
+                    _LOGGER.warning(
+                        "Skipping customer ID %s due to validation error: %s",
+                        customer.id,
+                        e,
+                    )
 
         if hashed_count > 0:
             await self.session.commit()
 
+        if skipped_count > 0:
+            _LOGGER.warning(
+                "Skipped %d customers with invalid data. "
+                "Please fix these customers manually.",
+                skipped_count,
+            )
+
         return hashed_count
diff --git a/src/alpine_bits_python/schemas.py b/src/alpine_bits_python/schemas.py
index 0ee730c..d3eebe2 100644
--- a/src/alpine_bits_python/schemas.py
+++ b/src/alpine_bits_python/schemas.py
@@ -103,9 +103,7 @@ class CustomerData(BaseModel):
     address_line: str | None = Field(None, max_length=255)
     city_name: str | None = Field(None, max_length=100)
     postal_code: str | None = Field(None, max_length=20)
-    country_code: str | None = Field(
-        None, min_length=2, max_length=2, pattern="^[A-Z]{2}$"
-    )
+    country_code: str | None = Field(None, min_length=2, max_length=2)
     address_catalog: bool | None = None
     gender: str | None = Field(None, pattern="^(Male|Female|Unknown)$")
     birth_date: str | None = Field(None, pattern=r"^\d{4}-\d{2}-\d{2}$")  # ISO format
@@ -119,11 +117,29 @@ class CustomerData(BaseModel):
             raise ValueError("Name cannot be empty or whitespace")
         return v.strip()
 
-    @field_validator("country_code")
+    @field_validator("country_code", mode="before")
     @classmethod
     def normalize_country_code(cls, v: str | None) -> str | None:
-        """Normalize country code to uppercase."""
-        return v.upper() if v else None
+        """Normalize country code to uppercase and validate format.
+
+        Runs in 'before' mode to normalize before other validations.
+        Accepts 2-letter country codes (case-insensitive) and normalizes
+        to uppercase ISO 3166-1 alpha-2 format.
+        """
+        if v is None or v == "":
+            return None
+
+        # Convert to string and strip whitespace
+        v = str(v).strip().upper()
+
+        # Validate it's exactly 2 letters
+        if len(v) != 2 or not v.isalpha():
+            raise ValueError(
+                f"Country code must be exactly 2 letters (ISO 3166-1 alpha-2), "
+                f"got '{v}'"
+            )
+
+        return v
 
     @field_validator("language")
     @classmethod