Lesson 2 of 6
Invoices and credit memos
6 min
Most supplier invoices at a manufacturer like Contoso refer to a purchase order and go through logistics invoice verification. This lesson covers the other kind: invoices without a purchase order, such as utilities, legal fees, rent or a one-off repair. They are posted directly against G/L accounts, so the person entering them decides the expense account, cost center and tax code. That freedom is why these invoices need good controls.
Where you post them
In SAP S/4HANA the app Create Supplier Invoice supports invoices without a purchase order reference, with items posted directly to G/L accounts. SAP's learning content notes that the Advanced variant of the app and the classic transaction MIRO can also post non-PO items to materials or assets, and that direct G/L posting must be enabled in invoice verification Customizing. Many finance teams in Private Edition still use the finance-side entry screen FB60 (and FB65 for credit memos), which posts a pure accounting document. Which route your project uses is a design decision; testers should test the one users will actually use, because approvals, parking and reporting can differ between them.
- HeaderCompany code 1710, supplier Lakeside Components, invoice date, posting date, reference (supplier's invoice number), amount, currency
- TaxTax code and either calculate tax or enter it; check the tax amount against the paper invoice
- Payment dataPayment terms default from the supplier's company code data; baseline date shown; payment block if needed
- G/L itemsExpense account, amount, cost center or other controlling object
- SimulateReview the journal entry: supplier credit, expense debit, input tax debit
- Post or parkPost if complete; park if it needs approval or more data
When posted, the journal entry credits the supplier (and so the payables reconciliation account) with the gross amount, debits the expense account with the net amount and debits input tax. For Contoso, a 1,000 USD plus tax repair invoice from Lakeside credits Lakeside, debits repairs expense on the Detroit maintenance cost center and debits the tax account determined by the tax code. In the US, sales and use tax handling depends heavily on the tax configuration and any external tax engine, so confirm the tax behavior with your tax team rather than assuming it.
Credit memos
A credit memo reduces what Contoso owes. It posts the opposite way: debit the supplier, credit the expense and tax. If the credit memo refers to a specific invoice (the invoice reference field in the payment data), it takes that invoice's payment terms and due date, and the payment run offsets the two together. A credit memo without an invoice reference is, per SAP's standard behavior, due on its baseline date unless the payment terms are activated for it. In practice this means unlinked credit memos are usable at once, which is usually what AP wants.
The duplicate invoice check
Paying the same invoice twice is one of the most common and most expensive AP errors. SAP's duplicate invoice check compares a new invoice with existing documents for the same supplier. The standard check uses the company code, supplier, currency, reference (the supplier's invoice number) and the invoice or document date; some releases and transactions also compare the amount. It only runs if the check double invoice indicator is set in the supplier's company code data, and by default the result is a warning, not an error. Projects often change the message to an error once the team trusts the reference data.
- Is the double invoice check set for this supplier in company code 1710?No → no check runs at all · Yes → continue
- Was the supplier's invoice number entered in the reference field?No → the check has nothing reliable to compare · Yes → continue
- Does an existing document match on company code, supplier, currency, reference and date?Yes → warning or error, depending on message settings · No → posting continues
- Is the message set to warning?Yes → the user can still post, so train users to stop and investigate · No → posting is blocked
What would you do?
Maria's team receives a scanned invoice from Lakeside Components for 4,250 USD, reference INV-4471. The system shows a warning that a document with the same reference already exists. The clerk says the amount is different, so it must be a new invoice. What should she do?
- Non-PO invoices post supplier credit, expense debit and input tax; the poster chooses the account and cost center.
- Create Supplier Invoice supports non-PO G/L items; FB60 and FB65 are the classic finance-side routes.
- A credit memo linked to an invoice takes that invoice's terms; an unlinked one is normally due at once.
- The duplicate check needs the supplier indicator and a consistent reference, and is a warning by default.
Check your understanding · not graded
Lesson check
1. Which field holds the supplier's own invoice number?
2. What must be set before the duplicate invoice check runs for a supplier?
3. A credit memo is entered without an invoice reference. When is it normally due?
4. What does a non-PO supplier invoice credit?