The term purchase invoice describes the buyer’s view of an incoming supplier invoice. It identifies the vendor, buyer, items supplied, dates, tax, total, payment terms, and any purchase-order reference. It does not mean the purchase has already been paid.
For example, a supplier invoice for 12 units at $75 shows a $900 subtotal before tax. The buyer records the $900 as a purchase and an amount payable, subject to the business’s accounting method and applicable rules. The supplier records the same transaction as a sale and amount receivable.
Purchase document comparison
How is a purchase invoice different from related documents?
The document name depends on who creates it, who records it, and whether it authorizes, requests, or confirms payment.
| Document | Created by | Main purpose | Typical timing |
|---|---|---|---|
| Purchase order | Buyer | Authorize a planned purchase | Before supply |
| Supplier invoice | Supplier | Request payment for supply | At the agreed billing event |
| Purchase invoice | Buyer records the supplier invoice | Record a purchase and amount payable | After receipt of the supplier invoice |
| Sales invoice | Supplier records its own invoice | Record a sale and amount receivable | When the invoice is issued |
| Receipt | Seller or payment provider | Confirm payment | After payment |
What information is on a purchase invoice?
A purchase invoice normally carries the supplier’s invoice number and issue date, the legal or trading identities of both parties, item descriptions, quantities, prices, discounts, tax, currency, total, due date, and payment instructions. Required fields depend on the location and transaction.
The buyer should preserve the supplier’s original number rather than replacing it with an internal invoice number. An internal document ID can be added separately so the source invoice remains traceable.
- Supplier invoice number and dates
- Supplier and buyer details
- Items, quantities, prices, tax, and total
- PO reference, due date, and payment terms
Purchase invoice vs purchase order
The buyer creates a purchase order before supply to authorize what may be bought. The supplier creates the invoice after the agreed billing event to request payment. The buyer then receives and records that document as a purchase invoice.
A PO does not prove delivery or payment, and a purchase invoice does not prove authorization. Comparing the invoice with the approved PO and receipt or service approval helps identify price, quantity, duplicate, or supplier differences.
- PO is created by the buyer
- Invoice is created by the supplier
- Purchase invoice is the buyer’s incoming-invoice record
- Receipt or approval confirms supply
Purchase invoice vs sales invoice
The names describe the same transaction from opposite sides. For the supplier, the document is a sales invoice because it records a sale and amount receivable. For the buyer, it is a purchase invoice because it records a purchase and amount payable.
The PDF does not need two labels. It is normally titled Invoice. The accounting system determines whether the document is entered in sales or purchases based on whether the business issued or received it.
- Supplier: sales invoice and receivable
- Buyer: purchase invoice and payable
- One source document, two accounting perspectives
- A receipt is separate proof of payment
How should a buyer process a purchase invoice?
Confirm the supplier, invoice number, dates, tax treatment, currency, bank details, and arithmetic. Match the invoice to the approved purchase order and evidence of delivery or service approval when those controls apply. Resolve exceptions before payment rather than editing the supplier’s document.
Record the approved amount and due date, schedule payment through the authorized process, and link the payment reference back to the invoice. Retain the original invoice, approvals, corrections, credits, and payment record for the period required by applicable accounting and tax rules.
- Check identity, references, and totals
- Match authorization and receipt evidence
- Resolve differences before payment
- Link approval, payment, and retention records
Official sources
These references support the regulatory information in this guide. Check the current page before making a decision.
- UK Government Invoice RequirementsLists core invoice fields including identifiers, parties, descriptions, dates, amounts, VAT, and total.
- Federal Acquisition Regulation 32.905: Invoice DocumentationProvides an official example of invoice documentation and references used to support a proper payment request.
Frequently asked questions
Questions about what is a purchase invoice? explained
Is a purchase invoice the same as a purchase order?
No. The buyer sends a purchase order to authorize a planned purchase. The supplier sends the invoice, which the buyer records as a purchase invoice.
Who creates a purchase invoice?
The supplier creates the invoice. The buyer receives it and records it as a purchase invoice or vendor bill in its accounts-payable process.
Does a purchase invoice prove payment?
No. It records an amount charged or payable. A receipt, bank record, processor confirmation, or other payment record confirms settlement.