# Purchase order (PO)

Buyer-issued document ordering goods/services, often referenced by an invoice.

## Definition

Buyer-issued document ordering goods/services, often referenced by an invoice.

## Explanation

Referencing PO numbers helps matching invoices to orders.

Commonly required in enterprise workflows.

## Related resources

- [Document references](/resources/glossary/document-reference)

## Related terms

- [Document reference](/resources/glossary/document-reference): Link from an invoice to another document (order, contract, prior invoice).
- [Contract reference](/resources/glossary/contract): Identifier linking an invoice to a contract or framework agreement.