Credit and debit notes under Phase 2: how to handle a return correctly

Under Phase 2, an issued invoice is permanent. Each invoice carries the hash of the one before it, so deleting or editing one breaks the chain from that point onward — and a broken chain is visible to the authority.

This is a feature, not an obstacle. It means you correct byadding a document, never by removing one.

The two correction documents

Credit note. Reduces what the customer owes. Used for returns, refunds, cancellations, and price reductions after the fact.

Debit note. Increases what the customer owes. Used when the original invoice undercharged — a missed item, an incorrect price, an omitted charge.

Both are electronic documents in their own right. Both carry the same cryptographic requirements as an invoice: UBL 2.1 XML, a UUID, the previous invoice hash, a cryptographic stamp and a QR code. Both follow the same route as the invoice they correct — reported within 24 hours for simplified, cleared before delivery for standard.

What a credit note must reference

The single most important field is thereference to the original invoice. A credit note that does not name the invoice it corrects is an unexplained reduction in your declared output VAT, which is exactly what an audit looks for.

Required, alongside the usual invoice fields:

• The original invoice number and its issue date
• The reason for the correction
• The corrected line items, quantities and amounts
• The VAT adjustment

Your point of sale should capture the reason as structured data, not free text an employee types differently every time.

The common shop scenarios

A customer returns one item from a five-item sale

Issue a credit note for that line only, referencing the original invoice. Do not void the invoice and re-issue — that is two errors instead of one correction.

A customer returns everything

A credit note for the full amount, referencing the original invoice. The original invoice remains in the chain; it is now fully credited.

The cashier rang up the wrong price and the customer already left

Credit note for the difference (if overcharged) or debit note (if undercharged). If the customer cannot be contacted for an undercharge, talk to your accountant about the right treatment before issuing anything.

An exchange — a different size of the same item

Two documents: a credit note for the returned item and a new invoice for the item taken. It feels heavy for a size swap and it is the correct treatment, which is why your POS should make it two taps rather than a procedure.

A sale was rung up twice by mistake

A credit note against the duplicate. Not a deletion.

What your POS must do

1. Refuse to delete invoices. A system that offers "void invoice" as a general button is teaching your staff a habit that breaks the chain.
2. Prompt for the original invoice. Returns should start by scanning the original receipt's QR or searching the invoice number.
3. Restrict who can issue credit notes. This is a permission, not a default. It is also the most common internal-theft vector in retail: a credit note with no goods coming back is cash out of the drawer.
4. Record a reason. Structured, from a list.
5. Return stock correctly. A returned item usually goes back into inventory; a damaged one goes to a write-off location, not back on the shelf.
6. Report the note on the same path as the invoice.

The internal-control angle

Credit notes deserve a weekly look, independent of compliance. Three questions:

• Which staff member issued the most credit notes this week, and is that explained by their shift pattern?
• Are there credit notes with no corresponding stock movement?
• Are there credit notes issued near closing time, disproportionately?

None of these proves anything on its own. All three together, repeatedly, is a pattern worth a conversation. Wameed's anomaly detection flags exactly this shape; seeWameed AI.

What Wameed does

Credit and debit notes are first-class documents with the original-invoice reference required, a structured reason list, a dedicated permission, automatic stock return with a separate damaged-goods path, and the same signing and reporting pipeline as invoices — including offline.

More on theZATCA page, and the wider requirements in thecomplete Phase 2 guide.

Not tax advice. Confirm treatment with your accountant or ZATCA.