diff --git a/alembic/versions/4990a9f1ada3_add_unique_constraints.py b/alembic/versions/4990a9f1ada3_add_unique_constraints.py
new file mode 100644
index 0000000..974f79d
--- /dev/null
+++ b/alembic/versions/4990a9f1ada3_add_unique_constraints.py
@@ -0,0 +1,28 @@
+"""add unique constraints
+
+Revision ID: 4990a9f1ada3
+Revises: 688af5ecd407
+Create Date: 2016-05-18 15:40:33.511871
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '4990a9f1ada3'
+down_revision = '688af5ecd407'
+branch_labels = None
+depends_on = None
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+    op.create_unique_constraint('uq_credit_card_id', 'credit_card', ['card_id'])
+    op.create_unique_constraint('uq_ofxsource_fid', 'ofxsource', ['fid'])
+    op.create_unique_constraint('uq_user_username', 'users', ['username'])
+
+
+def downgrade():
+    op.drop_constraint('uq_user_username', 'users', type_='unique')
+    op.drop_constraint('uq_ofxsource_fid', 'ofxsource', type_='unique')
+    op.drop_constraint('uq_credit_card_id', 'credit_card', type_='unique')
diff --git a/vanth/tables.py b/vanth/tables.py
index 9d6bbe5..6213bf2 100644
--- a/vanth/tables.py
+++ b/vanth/tables.py
@@ -1,6 +1,6 @@
 import chryso.constants
 from sqlalchemy import (Column, Date, DateTime, Float, ForeignKey, Integer,
-                        MetaData, String, Table, func)
+                        MetaData, String, Table, UniqueConstraint, func)
 from sqlalchemy.dialects.postgresql import UUID
 
 metadata = MetaData(naming_convention=chryso.constants.CONVENTION)
@@ -14,6 +14,7 @@ User = Table('users', metadata,
     Column('created_at',    DateTime,    nullable=False, server_default=func.now()),
     Column('updated_at',    DateTime,    nullable=False, server_default=func.now(), onupdate=func.now()),
     Column('deleted_at',    DateTime,    nullable=True),
+    UniqueConstraint('username', name='uq_user_username'),
 )
 
 CreditCard = Table('credit_card', metadata,
@@ -30,15 +31,17 @@ CreditCard = Table('credit_card', metadata,
     Column('created',           DateTime(),     nullable=False, server_default=func.now()),
     Column('updated',           DateTime(),     nullable=False, server_default=func.now(), onupdate=func.now()),
     Column('deleted',           DateTime(),     nullable=True),
+    UniqueConstraint('card_id', name='uq_credit_card_id'),
 )
 
 OFXSource = Table('ofxsource',  metadata,
     Column('uuid',              UUID(as_uuid=True),         primary_key=True),
     Column('name',              String(255),     nullable=False), # The name of the institution such as 'America First Credit Union'
     Column('fid',               String(255),     nullable=False), # The FID of the institution, such as 54324
-    Column('bankid',            String(255),     nullable=False), # The bank ID of the institution such as 324377516
+    Column('bankid',            String(255),     nullable=False), # The bank ID of the institution such as 324377516. This may be a routing number
     Column('created',           DateTime(),      nullable=False, server_default=func.now()),
     Column('updated',           DateTime(),     nullable=False, server_default=func.now(), onupdate=func.now()),
+    UniqueConstraint('fid', name='uq_ofxsource_fid'),
 )
 
 OFXAccount = Table('ofxaccount', metadata,