What Is a Debit Note? The 7 Essential Details It Must Show
A supplier invoices you for 100 units. Ten arrive damaged. You send a document asking for the invoice to be reduced, and you call it a debit note.
The same week, another supplier says their invoice was understated by £400 and sends you a document to collect the difference. They also call it a debit note.
Both are correct, which is why the question what is a debit note gets answered differently depending on who you ask, and why so many finance teams file them in the wrong place. Here is the version that covers both: what the document does, who issues it, the UK rules, and how to tell it apart from a credit note.
What is a debit note?
A debit note is a document that increases the amount owed under a transaction that has already been invoiced.
That definition holds in every context. It does not cancel the original invoice and it is not a second invoice. It sits alongside the original and moves the balance one way only: up, for whoever receives it. The confusion comes from the word “debit”, because which account is debited depends on who issued the note.
Who issues a debit note?
Either party can. That single fact resolves most of the confusion, and almost no explainer states it plainly.
A supplier issues a debit note when the original invoice was too low: the price was understated, a charge was left off, a quantity was short billed, or an uplift was agreed after invoicing. The supplier is collecting the shortfall.
A buyer issues a debit note when returning goods or claiming money back. Damaged stock, a quantity discrepancy, an overcharge. The buyer is debiting the supplier’s account in their own ledger and saying so.
Same name, opposite directions. Both are consistent in accounting terms, because the issuer is recording a debit in their own books. The practical point: when one lands on your desk, the first question is not “what is a debit note” but “who sent it”, because that decides whether you owe more or are about to be credited.
Debit note vs credit note
Four lines is all it takes.
| Debit note | Credit note | |
|---|---|---|
| Effect on balance | Increases the amount owed | Decreases the amount owed |
| Usually issued by | Either party | The supplier |
| Typical trigger | Undercharge, return claim, extra charge | Overcharge, accepted return, discount |
| Nature | A request or a charge | A confirmation |
In the most common sequence the two work as a pair. A buyer claims for ten damaged units; the supplier checks it, agrees, and issues a credit note. One asked, the other settled it.
That pairing is why a buyer’s claim alone does not reduce what you owe. Until the credit note is issued, the original invoice stands at full value in the supplier’s ledger, and paying short is a reliable way into a dispute you did not need.
The UK VAT rules, which are stricter than most people expect
If VAT is involved, this is not just paperwork. HMRC sets out when one is required and what it must contain.
The rule splits by direction. A debit note is for an increase in price; a credit note is for a decrease. Both must be issued within 14 days.
Those 14 days run from the date the supplier and the customer agree the increase, not from the original invoice date. The agreement is the trigger, and that is the part most commonly missed when an adjustment is negotiated over weeks.
For a credit note the clock works differently: the 14 days start when the supplier actually refunds the customer, because a VAT adjustment for a decrease requires a real refund in money, not just paperwork.
One useful exemption: if the price change falls inside the same VAT period as the original supply, it is not a formal adjustment at all. The 14 day rule applies only to adjustments crossing periods.
The full HMRC position sits in the VAT supply and consideration manual, in its guidance on credit and debit notes, and it is worth reading if you issue them regularly.
What to put on a debit note
Where VAT applies, HMRC prescribes the contents. Even where it does not, this is the right list, because one that cannot be matched to an invoice gets queried:
- An identifying number and the date of issue
- The supplier’s name, address and VAT registration number
- The customer’s name and address
- The number and date of the original invoice or invoices it adjusts
- A description of the goods or services concerned
- The price change, excluding VAT
- The VAT rate and the amount of VAT in sterling
Two of those do the heavy lifting. The invoice reference lets the recipient find the transaction in seconds. And stating the change rather than a new total prevents the costliest error here: a recipient who reads the figure as a replacement invoice and pays it on top of the original.
Then label it clearly in one line. “Debit note DN-0142: price increase agreed 12 October on invoice INV-1088, additional freight.” That sentence prevents more queries than the rest of the document combined.
Debit note vs invoice
It is not a small invoice, and treating it as one causes real problems. An invoice creates a charge for a supply; an adjustment amends a charge that already exists, and the original invoice stays in the ledger at full value with the adjustment attached.
That matters three ways. Invoice numbering stays clean, so these get their own series. Your VAT return treats the change as an amendment to the earlier supply, not a new one. And your aged debtors report shows one transaction with an adjustment rather than two unrelated amounts. If you are still working out what belongs on the original document, our guide to writing an invoice properly covers that, and purchase order vs invoice explains the document that should have caught the price before it was billed.
When you actually need one
Four situations account for nearly all of them.
An undercharge you spotted yourself. You invoiced at the old rate, or left a line off. Reference the original invoice rather than raising a second one, which accounts payable cannot easily match.
A price increase agreed after invoicing. Common on long projects and anything with a materials or freight element. Get the agreement in writing, date it, and issue within 14 days where VAT applies.
Goods returned to a supplier. Record what is going back and what you expect to be credited, and send it the day the goods leave, with the carrier reference on it.
A quantity or quality claim. Short delivery, damaged stock, product off specification. Photographs plus a delivery note reference settle it faster than three emails.
What it is not for: late payment. Interest and compensation on an overdue invoice are a separate statutory entitlement, covered in our guide to the late payment fee.
How to record one in your books
The entries are simple once the direction is clear.
As the supplier: debit accounts receivable, credit sales, and credit the VAT control account for the additional VAT. The customer’s balance goes up.
As the buyer: debit the supplier’s account in accounts payable and credit purchases or purchase returns, with the VAT element reversed.
One rule saves a lot of time: do not post a buyer’s claim as a settled adjustment until the credit note arrives. Hold it on a pending list, then match the two, close the claim and pay the net. If nothing arrives in two weeks, chase it once with the reference. Most of the money lost here is lost quietly, in claims nobody followed up.
Where it fits with your other paperwork
The sequence runs: purchase order, delivery, invoice, adjustment, payment, confirmation. Adjustments are the step most businesses handle informally over email, which works until there is a dispute or an audit, at which point an email thread is not a document trail.
Downstream, both notes belong on the monthly statement of account with their references, so the customer can reconcile without asking, and a remittance advice listing the invoice and both adjustments removes the last place an allocation can go wrong. If a due date is unclear, net 30 payment terms explains how the clock is counted.
Frequently asked questions
What is a debit note in simple terms?
A document that increases the amount owed on an already invoiced transaction, issued either by a supplier collecting an undercharge or by a buyer claiming money back.
Who issues one, the buyer or the seller?
Both do, in different situations. A supplier issues one for a price increase; a buyer issues one for returns or claims.
Is a debit note the same as an invoice?
No. An invoice creates a charge; a debit note adjusts one that already exists and carries its own numbering series.
How long do I have to issue one for VAT?
Fourteen days from the date the price increase is agreed, where the adjustment crosses VAT periods. Within the same period you simply account for the corrected figure. It must show the price change excluding VAT, the VAT rate and the VAT amount in sterling, plus the original invoice reference.
The short version
So, what is a debit note? A document that moves an already invoiced balance upward for whoever receives it. A supplier sends one to collect an undercharge; a buyer sends one to claim for returns or errors.
Reference the original invoice, state the change rather than a new total, label it clearly, and give it its own numbering series. Where VAT applies, issue it within 14 days of the agreed price change with the seven fields HMRC requires. Then treat a buyer’s claim as a claim until the credit note arrives. That habit is the difference between a tidy ledger and a year end spent reconciling adjustments nobody agreed to.
