diff --git a/alembic/versions/2025_11_19_1457-08fe946414d8_add_hashed_customer_id_to_reservations_.py b/alembic/versions/2025_11_19_1457-08fe946414d8_add_hashed_customer_id_to_reservations_.py
new file mode 100644
index 0000000..6622469
--- /dev/null
+++ b/alembic/versions/2025_11_19_1457-08fe946414d8_add_hashed_customer_id_to_reservations_.py
@@ -0,0 +1,65 @@
+"""add hashed_customer_id to reservations with cascade delete
+
+Revision ID: 08fe946414d8
+Revises: 70b2579d1d96
+Create Date: 2025-11-19 14:57:27.178924
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = '08fe946414d8'
+down_revision: Union[str, Sequence[str], None] = '70b2579d1d96'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Upgrade schema."""
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.alter_column('hashed_customers', 'customer_id',
+               existing_type=sa.INTEGER(),
+               nullable=True)
+    op.drop_constraint(op.f('hashed_customers_customer_id_fkey'), 'hashed_customers', type_='foreignkey')
+    op.create_foreign_key(None, 'hashed_customers', 'customers', ['customer_id'], ['id'], ondelete='SET NULL')
+    op.drop_constraint(op.f('reservations_customer_id_fkey'), 'reservations', type_='foreignkey')
+    op.create_foreign_key(None, 'reservations', 'customers', ['customer_id'], ['id'], ondelete='SET NULL')
+
+    # Add hashed_customer_id column to reservations with cascade delete
+    op.add_column('reservations', sa.Column('hashed_customer_id', sa.Integer(), nullable=True))
+    op.create_index(op.f('ix_reservations_hashed_customer_id'), 'reservations', ['hashed_customer_id'], unique=False)
+    op.create_foreign_key(None, 'reservations', 'hashed_customers', ['hashed_customer_id'], ['id'], ondelete='CASCADE')
+    # ### end Alembic commands ###
+
+    # Data migration: Populate hashed_customer_id from customer relationship
+    connection = op.get_bind()
+    update_stmt = sa.text("""
+        UPDATE reservations r
+        SET hashed_customer_id = hc.id
+        FROM hashed_customers hc
+        WHERE r.customer_id = hc.customer_id
+          AND hc.customer_id IS NOT NULL
+    """)
+    connection.execute(update_stmt)
+
+
+def downgrade() -> None:
+    """Downgrade schema."""
+    # ### commands auto generated by Alembic - please adjust! ###
+    # Drop the hashed_customer_id column and its constraints
+    op.drop_constraint(None, 'reservations', type_='foreignkey')
+    op.drop_index(op.f('ix_reservations_hashed_customer_id'), table_name='reservations')
+    op.drop_column('reservations', 'hashed_customer_id')
+
+    op.drop_constraint(None, 'reservations', type_='foreignkey')
+    op.create_foreign_key(op.f('reservations_customer_id_fkey'), 'reservations', 'customers', ['customer_id'], ['id'])
+    op.drop_constraint(None, 'hashed_customers', type_='foreignkey')
+    op.create_foreign_key(op.f('hashed_customers_customer_id_fkey'), 'hashed_customers', 'customers', ['customer_id'], ['id'])
+    op.alter_column('hashed_customers', 'customer_id',
+               existing_type=sa.INTEGER(),
+               nullable=False)
+    # ### end Alembic commands ###
diff --git a/src/alpine_bits_python/conversion_service.py b/src/alpine_bits_python/conversion_service.py
index 1b4b49a..9e77579 100644
--- a/src/alpine_bits_python/conversion_service.py
+++ b/src/alpine_bits_python/conversion_service.py
@@ -253,7 +253,8 @@ class ConversionService:
             # Load all reservations with their hashed customers in one query
             from sqlalchemy.orm import selectinload
             query = select(Reservation).options(
-                selectinload(Reservation.customer).selectinload(Customer.hashed_version)
+                selectinload(Reservation.customer).selectinload(Customer.hashed_version),
+                selectinload(Reservation.hashed_customer)
             )
             result = await session.execute(query)
             reservations = result.scalars().all()
@@ -265,9 +266,11 @@ class ConversionService:
                 hotel_code = reservation.hotel_code
                 if hotel_code not in self._reservation_cache:
                     self._reservation_cache[hotel_code] = []
-                # Cache the hashed customer instead of raw customer
+                # Cache the hashed customer - prefer direct relationship, fall back to customer relationship
                 hashed_customer = None
-                if reservation.customer and reservation.customer.hashed_version:
+                if reservation.hashed_customer:
+                    hashed_customer = reservation.hashed_customer
+                elif reservation.customer and reservation.customer.hashed_version:
                     hashed_customer = reservation.customer.hashed_version
                 self._reservation_cache[hotel_code].append(
                     (reservation, hashed_customer)
diff --git a/src/alpine_bits_python/db.py b/src/alpine_bits_python/db.py
index adb9651..9a5aefb 100644
--- a/src/alpine_bits_python/db.py
+++ b/src/alpine_bits_python/db.py
@@ -478,6 +478,7 @@ class Reservation(Base):
     __tablename__ = "reservations"
     id = Column(Integer, primary_key=True)
     customer_id = Column(Integer, ForeignKey("customers.id", ondelete="SET NULL"))
+    hashed_customer_id = Column(Integer, ForeignKey("hashed_customers.id", ondelete="CASCADE"))
     unique_id = Column(String, unique=True)
     md5_unique_id = Column(String(32), unique=True)  # max length 32 guaranteed
     start_date = Column(Date)
@@ -507,6 +508,7 @@ class Reservation(Base):
     room_classification_code = Column(String)
     room_type = Column(String)
     customer = relationship("Customer", back_populates="reservations")
+    hashed_customer = relationship("HashedCustomer", backref="reservations")
 
 
 # Table for tracking acknowledged requests by client
diff --git a/src/alpine_bits_python/reservation_service.py b/src/alpine_bits_python/reservation_service.py
index 0e48758..12c0a2a 100644
--- a/src/alpine_bits_python/reservation_service.py
+++ b/src/alpine_bits_python/reservation_service.py
@@ -7,7 +7,7 @@ from typing import Optional
 from sqlalchemy import and_, select
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from .db import AckedRequest, Customer, Reservation
+from .db import AckedRequest, Customer, HashedCustomer, Reservation
 from .schemas import ReservationData
 
 
@@ -63,6 +63,19 @@ class ReservationService:
         reservation = self._convert_reservation_data_to_db(
             reservation_data, customer_id
         )
+
+        # Automatically populate hashed_customer_id from the customer
+        # Since hashed_customer is always created when a customer is created,
+        # we can get it by querying for the hashed_customer with matching customer_id
+        hashed_customer_result = await self.session.execute(
+            select(HashedCustomer).where(
+                HashedCustomer.customer_id == customer_id
+            )
+        )
+        hashed_customer = hashed_customer_result.scalar_one_or_none()
+        if hashed_customer:
+            reservation.hashed_customer_id = hashed_customer.id
+
         self.session.add(reservation)
 
         if auto_commit: