What Is a Blanket Purchase Order?

A blanket purchase order is a framework for a long-term agreement: the buyer agrees to a total quantity, and the seller delivers it in smaller shipments over time. Microsoft's documentation for Dynamics 365 Business Central, an ERP, describes blanket sales orders and blanket purchase orders this way and says the steps are the same on the sales and the purchasing side.

According to that documentation, a blanket order is typically used when a customer buys a large quantity that is delivered in small shipments over a period of time. Blanket orders often cover only one item with predetermined delivery dates. The main reason to use a blanket order rather than a regular order is that quantities entered on it don't affect item availability, so it can serve as a worksheet for monitoring, forecasting, and planning.

Business Central applies a few rules to orders created from a blanket order:

• The order line quantity must not exceed the quantity of the associated blanket order line, or the order can't be posted.
• The blanket order number and line number are recorded on each order line created from it.
• After orders cover the full quantity of a blanket line, no other order can be created for that line. To add quantity, you increase the Quantity field on the blanket line.
• A Statistics page summarizes the blanket order's quantities, invoicing, shipping and any prepaid amounts.

• Standard purchase order: one order for specific items, quantities and a delivery date.
• Blanket purchase order: an agreement covering a total quantity over time. In Business Central, its quantities don't affect item availability, and regular orders are created from it as each shipment comes due.

In US federal purchasing, a related tool has its own rules. FAR 13.303-1 defines a blanket purchase agreement (BPA) as a simplified method of filling anticipated repetitive needs for supplies or services by establishing "charge accounts" with qualified sources of supply.

A plant agrees to buy 1,000 filters from a distributor at $12.00 each, $12,000 in total, delivered over four weeks. The blanket order has four lines of 250 units:

• Week 1: the first line becomes an order: 250 x $12.00 = $3,000.
• Week 2: the second line becomes an order for another $3,000.
• After two shipments: 500 units have shipped and been invoiced, so 1,000 - 500 = 500 units, worth $6,000, remain on the blanket order.

Shopify B2B is on the Basic, Grow, Advanced and Shopify Plus plans, and PO numbers are available on all of them. At checkout, B2B customers have the option to enter a purchase order number for the order, and customers can view that number on the order status page. When you create a B2B draft order, you can add a purchase order number in its PO number section.

The blanket agreement itself, with its total quantity, the orders drawn against it and the remaining balance, sits in the system that holds the agreement, such as the ERP.

Uncap's page on industrial supply and MRO describes the approach: a release against an existing blanket PO is handled as a release, with the remaining balance visible, rather than forced through a checkout that creates reconciliation work. Uncap Connect keeps Shopify and the ERP in sync, and blanket purchase order releases move between the systems that own them, with the ERP remaining the system of record.

• Purchase order
• Sales order
• EDI 830
• EDI 850
• Purchase requisition
• Procure-to-pay

• Microsoft Learn: Work with blanket sales orders or blanket purchase orders
• FAR Subpart 13.3: Simplified Acquisition Methods
• Shopify Help Center: B2B plan features