Blanket Purchase Orders

A blanket purchase order (also called a standing PO, framework order, or master PO) is a long-term purchase agreement with a supplier that authorises multiple deliveries or service calls up to an agreed total value or over a defined period, without requiring a new purchase order for each transaction. Instead of raising a specific PO for each delivery of workshop consumables, for example, a blanket PO might authorise AU$50,000 of consumable purchases from a specific supplier over the next 12 months, with individual deliveries and invoices drawing down against the blanket PO total.

Blanket POs are most appropriate for: recurring purchases of the same or similar items from the same supplier; high-frequency, low-value purchases where the administrative cost of individual POs is disproportionate; and services delivered on an ongoing or as-needed basis (cleaning, maintenance, security) where the service is continuous but individual call-outs or service visits cannot be pre-quantified.

AP processing against a blanket PO

When an invoice arrives for a purchase covered by a blanket PO, the AP two-way or three-way match process checks the invoice against the blanket PO rather than a specific transaction PO. The match confirms that the supplier is the blanket PO supplier, the goods or services are within the approved category, the invoice amount does not exceed the remaining available balance on the blanket PO, and (for three-way match) a goods receipt has been recorded against the blanket PO for the items invoiced.

The blanket PO balance depletes as invoices are matched against it. When the balance is approaching exhaustion -- typically when 80 to 90 percent of the total value has been drawn down -- the AP system should alert the procurement team to either renew the blanket PO or raise a new one. Processing invoices against an exhausted blanket PO creates an over-commitment -- the business is effectively approving spend beyond what was originally authorised -- and should be treated as an exception requiring management review rather than being silently processed.

Blanket POs and spend control

Blanket POs improve spend control for recurring relationships by creating a defined spending envelope that is agreed in advance, rather than having each individual purchase approved without reference to cumulative spend. A department that has a AU$20,000 blanket PO for IT consumables has a clear limit; spend beyond that limit requires a new PO and therefore new approval. This creates a natural checkpoint for reviewing whether the spend category is budgeted and managed effectively without requiring individual approval for every AU$50 USB cable.