diff --git a/alembic/versions/0014_currency_unique_fix.py b/alembic/versions/0014_currency_unique_fix.py
new file mode 100644
index 0000000..273d787
--- /dev/null
+++ b/alembic/versions/0014_currency_unique_fix.py
@@ -0,0 +1,35 @@
+"""Fix currency unique constraint — tenant-scoped instead of global.
+
+Revision ID: 0014_currency_unique_fix
+Revises: 0013_addresses
+Create Date: 2026-07-04
+"""
+
+from __future__ import annotations
+
+from typing import Sequence, Union
+
+from alembic import op
+
+revision: str = "0014_currency_unique_fix"
+down_revision: Union[str, None] = "0013_addresses"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # Drop the old global unique constraint on currencies.code
+    op.execute("ALTER TABLE currencies DROP CONSTRAINT IF EXISTS currencies_code_key")
+    op.execute("DROP INDEX IF EXISTS currencies_code_key")
+
+    # Add tenant-scoped unique constraint
+    op.create_unique_constraint(
+        "uq_currency_tenant_code",
+        "currencies",
+        ["tenant_id", "code"],
+    )
+
+
+def downgrade() -> None:
+    op.drop_constraint("uq_currency_tenant_code", "currencies", type_="unique")
+    op.execute("ALTER TABLE currencies ADD CONSTRAINT currencies_code_key UNIQUE (code)")