How to Post a Vendor Invoice in SAP: A Step-by-Step Guide

What is a Vendor Invoice in SAP?

A vendor invoice in SAP is the formal record of a purchase your company owes money for. Whether you've received goods, services, or utilities, the vendor invoice creates a liability in your Financial Accounting (FI) module and is the trigger for the automatic payment process.

There are two main ways to post a vendor invoice in SAP — and which one you use depends on whether a purchase order (PO) exists.

Method 1: Posting Without a Purchase Order (FB60)

Use FB60 when there is no purchase order — for example, rent, utilities, or professional services. This is a direct FI document entry.

1. Enter transaction code FB60 in the command field.
2. Select the vendor account from your vendor master (created in XK01). The system auto-populates payment terms and bank details from the master record.
3. Enter the invoice date and posting date. Note: the invoice date drives the payment due date; the posting date determines which fiscal period the document hits.
4. Enter the amount and currency. If the invoice is in a foreign currency, SAP will calculate the exchange rate difference automatically based on the translation rate type configured in OB08.
5. Select the G/L account for the expense or asset being expensed. This is the offset account that balances the vendor liability.
6. Add the cost object (cost centre, order, or WBS element) if required by your controlling configuration.
7. Click Simulate to preview the accounting document before posting — always check debits equal credits.
8. Click Post. SAP generates a document number (starting with 1 for vendor invoices in most configurations).

Method 2: Invoice Verification Against a PO (MIRO)

Use MIRO when a purchase order exists — this is the standard three-way match process in SAP Materials Management (MM). It checks the invoice against the PO and the goods receipt (GR).

1. Enter transaction code MIRO.
2. Select transaction type Invoice (not Credit Memo).
3. Enter the invoice date and the PO number in the reference field. SAP auto-populates all PO line items that have been goods receipted.
4. Enter the amount from the vendor invoice. If it matches the expected amount, the traffic light turns green.
5. Verify the tax code — this is critical for VAT compliance. The system suggests a tax code based on the PO but you should confirm it matches the vendor invoice.
6. Check the balance field — it must be 0.00 before you can post. Any discrepancy means the invoice amount doesn't match what was delivered and receipted.
7. Click Post. SAP creates both an MM material document and an FI accounting document simultaneously.

Understanding the Accounting Behind the Posting

When you post a vendor invoice, SAP creates a double-entry accounting document:

• Debit: Expense account or GR/IR clearing account (balance sheet item if using MIRO)
• Credit: Vendor account (creates the liability in accounts payable)

The vendor account is a reconciliation account — postings go to a sub-ledger (AP ledger) and are automatically summarised in the main G/L account defined in the vendor account group.

Common Errors When Posting Vendor Invoices

"Period not open" — The posting date falls in a closed fiscal period. Fix: either change the posting date to an open period, or ask your FI administrator to open the period in OB52.

"Account not defined" — The G/L account determination for the tax code or vendor account group is missing. Fix: check the automatic account assignment in OBYC (for MIRO) or the chart of accounts configuration.

"Balance in transaction currency" — The debit and credit amounts don't balance. Fix: check that you haven't entered an incorrect amount or currency on the invoice line items.

Invoice blocked for payment — MIRO applies a payment block if the invoice amount exceeds the PO value by more than the tolerance limit configured in OMR6. Your AP team can release it in MRBR.

Key Tables and Reports

Once posted, you can view vendor invoices in:

• FBL1N — Vendor line item display (open items, cleared items, all items)
• MIR4 — Display an MIRO document
• Table BKPF — Accounting document header
• Table BSEG — Accounting document line items (vendor, G/L, tax lines)

Next Steps After Posting

Once the vendor invoice is posted, it enters the payment process. The F110 automatic payment program will pick it up on the due date and create a payment document that clears the open item on the vendor account.

Ready to practice? Automate & Graduate has interactive SAP modules, flashcards, and AI-powered practice exercises to help you master accounts payable workflows — including hands-on simulations of the FB60 and MIRO posting process.