diff --git a/corepos/db/office_op/model.py b/corepos/db/office_op/model.py
index 0e8bf49..8e24e05 100644
--- a/corepos/db/office_op/model.py
+++ b/corepos/db/office_op/model.py
@@ -1547,3 +1547,121 @@ class BatchItem(Base):
 
     def __str__(self):
         return self.upc or ""
+
+
+class PurchaseOrder(Base):
+    """
+    Represents a purchase order.
+    """
+    __tablename__ = 'PurchaseOrder'
+    # TODO: would be simpler to declare these, but is it safe?
+    # __table_args__ = (
+    #     sa.ForeignKeyConstraint(['vendorID'], ['vendors.vendorID']),
+    #     sa.ForeignKeyConstraint(['storeID'], ['Stores.storeID']),
+    # )
+
+    orderID = sa.Column(sa.Integer(), nullable=False, primary_key=True, autoincrement=True)
+    id = orm.synonym('orderID')
+
+    vendor_id = sa.Column('vendorID', sa.Integer(), nullable=True)
+    vendor = orm.relationship(
+        Vendor,
+        primaryjoin=Vendor.id == vendor_id,
+        foreign_keys=[vendor_id])
+
+    store_id = sa.Column('storeID', sa.Integer(), nullable=True)
+    store = orm.relationship(
+        Store,
+        primaryjoin=Store.id == store_id,
+        foreign_keys=[store_id])
+
+    creation_date = sa.Column('creationDate', sa.DateTime(), nullable=True)
+
+    placed = sa.Column(sa.Boolean(), nullable=True, default=False)
+
+    placed_date = sa.Column('placedDate', sa.DateTime(), nullable=True)
+
+    user_id = sa.Column('userID', sa.Integer(), nullable=True)
+
+    vendor_order_id = sa.Column('vendorOrderID', sa.String(length=25), nullable=True)
+
+    vendor_invoice_id = sa.Column('vendorInvoiceID', sa.String(length=25), nullable=True)
+
+    standing_id = sa.Column('standingID', sa.Integer(), nullable=True)
+
+    inventory_ignore = sa.Column('inventoryIgnore', sa.Boolean(), nullable=True, default=False)
+
+    transfer_id = sa.Column('transferID', sa.Integer(), nullable=True)
+
+    notes = association_proxy('notes', 'notes')
+
+    def __str__(self):
+        return "#{} for {}".format(self.id, self.vendor or "??")
+
+
+class PurchaseOrderItem(Base):
+    """
+    Represents a line item in a purchase order.
+    """
+    __tablename__ = 'PurchaseOrderItems'
+    __table_args__ = (
+        sa.ForeignKeyConstraint(['orderID'], ['PurchaseOrder.orderID']),
+    )
+
+    order_id = sa.Column('orderID', sa.Integer(), nullable=False,
+                         primary_key=True, autoincrement=False)
+    order = orm.relationship(PurchaseOrder, backref=orm.backref('items'))
+
+    sku = sa.Column(sa.String(length=13), nullable=False,
+                    primary_key=True)
+
+    quantity = sa.Column(sa.Numeric(precision=10, scale=2), nullable=True)
+
+    unit_cost = sa.Column('unitCost', sa.Numeric(precision=10, scale=4), nullable=True)
+
+    case_size = sa.Column('caseSize', sa.Float(), nullable=True)
+
+    received_date = sa.Column('receivedDate', sa.DateTime(), nullable=True)
+
+    received_quantity = sa.Column('receivedQty', sa.Float(), nullable=True)
+
+    received_total_cost = sa.Column('receivedTotalCost', sa.Numeric(precision=10, scale=4), nullable=True)
+
+    unit_size = sa.Column('unitSize', sa.String(length=25), nullable=True)
+
+    brand = sa.Column(sa.String(length=50), nullable=True)
+
+    description = sa.Column(sa.String(length=50), nullable=True)
+
+    internal_upc = sa.Column('internalUPC', sa.String(length=13), nullable=True)
+
+    sales_code = sa.Column('salesCode', sa.Integer(), nullable=True)
+
+    is_special_order = sa.Column('isSpecialOrder', sa.Boolean(), nullable=True,
+                                 default=False)
+
+    # TODO: this probably is FK to e.g. User.id ?
+    received_by = sa.Column('receivedBy', sa.Integer(), nullable=True,
+                            default=0)
+
+    def __str__(self):
+        return self.description or ""
+
+
+class PurchaseOrderNote(Base):
+    """
+    Represents a note attached to a purchase order.
+    """
+    __tablename__ = 'PurchaseOrderNotes'
+    __table_args__ = (
+        sa.ForeignKeyConstraint(['orderID'], ['PurchaseOrder.orderID']),
+    )
+
+    order_id = sa.Column('orderID', sa.Integer(), nullable=False,
+                         primary_key=True, autoincrement=False)
+    order = orm.relationship(PurchaseOrder, backref=orm.backref('notes'))
+
+    notes = sa.Column(sa.Text(), nullable=True)
+
+    def __str__(self):
+        return self.notes or ""