A July invoice has already been declared, but in August the customer returns the goods or the parties agree a lower price. Should the accountant reopen July, or reduce August VAT? The answer does not depend on which month looks cleaner in the ledger. It depends on whether the commercial facts changed later or the original invoice and VAT return were wrong from the start.
In my 15+ years in Estonian accounting, I have seen credit-note problems start when those two cases are treated as the same correction. The EMTA guidance on VAT adjustments separates them clearly. This guide applies that distinction to an ordinary Estonian VAT invoice, the KMD period, the purchaser's input VAT and the supporting document trail.
Start with the reason: changed transaction or original error
Under the Value-Added Tax Act, §§ 27, 29 and 37, a cancellation or price reduction after the original return has been filed is adjusted in the tax period in which the invoice is cancelled or the credit invoice is submitted. This is a later change in the transaction, not an admission that the original KMD was false when filed.
A different route applies when the transaction never changed. If the seller originally used the wrong VAT rate, omitted taxable supply or declared the same invoice twice, the earlier KMD contains an error. Correct the invoice evidence and amend that earlier tax period. Do not issue a current credit note only to avoid reopening the incorrect return.
| What happened | Correct route | VAT period |
|---|---|---|
| Goods returned or sale cancelled later | Credit note linked to original invoice | Credit-note period |
| Price reduced after the original sale | Credit note for the agreed reduction | Credit-note period |
| Original invoice or KMD was wrong from day one | Correct evidence and amend KMD | Original period |
| Customer has merely not paid | Collection or bad-debt review, not a credit note | Depends on § 29¹ conditions |
The unpaid-invoice line matters. A credit note changes the transaction; non-payment does not. If the sale remains valid, use the separate irrecoverable-debt rules only when all statutory conditions are met.
Make the correction document traceable to one original invoice
The EMTA guidance on invoices and credit invoices treats a document, including a credit invoice, as an invoice when it amends an initial invoice and refers to that invoice. A customer balance entry or an email agreeing a refund is useful evidence, but it is not a substitute for a traceable correction document.
Use a new document number and the real issue date. Identify the original invoice, explain the commercial reason, and show the negative taxable value and VAT by rate. The correction follows the original supply's VAT treatment. A 2026 credit note can therefore carry an older 22% or 20% rate when it corrects a genuine sale made under that rate; it should not be forced to 24% merely because that is today's standard rate.
- new credit-note number and actual issue date
- original invoice number and date
- customer, supply and reason for the reduction or cancellation
- taxable value, VAT rate and VAT amount being reversed
- amount to refund or leave as credit on the customer account
Store the original invoice, return or discount approval, credit note and settlement evidence together. That chain lets the purchaser and accountant reach the same answer without reconstructing the sale months later.
Seller and purchaser should adjust the same document period
When a later commercial change is documented by a credit note, the seller reduces taxable supply and output VAT in the credit-note period. A VAT-registered purchaser that deducted the original input VAT reduces that deduction for the period in which it receives the credit note. The document date, delivery to the customer and both ledgers should therefore be aligned before KMD is filed.
If the partner's invoices belong in KMD INF, the EMTA instructions for sales invoices in KMD INF Part A requires the numerical credit-note data to be shown with minus signs. Check the current EUR 1,000 partner threshold and the relevant Part A or Part B scope rather than assuming every small retail correction belongs in the annex.
- Confirm why the transaction changed and who approved it.
- Issue and send the credit note with a reference to the original invoice.
- Post the negative revenue or purchase amount and VAT in the correct current period.
- Match the refund, offset or remaining balance to the same customer or supplier.
- Reconcile KMD, KMD INF where applicable, the VAT ledger and both invoice records.
Worked example: a full return after July KMD was filed
An Estonian VAT payer sells goods in July for EUR 1,240 including 24% VAT. The taxable value is EUR 1,000 and output VAT is EUR 240. The seller and purchaser file July correctly. In August the customer returns all goods under the agreed return terms, and the seller issues a credit note for the full amount.
The August credit note shows EUR -1,000 taxable value and EUR -240 VAT, total EUR -1,240. The seller reduces August taxable supply and output VAT; the purchaser reduces August input VAT. July remains unchanged because the July sale and July KMD were correct at the time. If the seller instead discovers that July used the wrong VAT treatment from the start, the correction belongs to July rather than this August route.
| Record | July | August |
|---|---|---|
| Seller taxable value | EUR 1,000 | EUR -1,000 |
| Seller output VAT | EUR 240 | EUR -240 |
| Purchaser input VAT | EUR 240 deducted | EUR 240 reduction |
| Main evidence | Original invoice and delivery | Return approval and credit note |
Do not copy this domestic 24% example blindly to intra-Community supplies, exports, reverse-charge services or OSS sales. Their reporting route follows the original transaction and may require a separate correction method.
Do not backdate a credit note to make the customer ledger look tidy. First write one sentence explaining what changed and when. That sentence usually tells the accountant whether to use the current credit-note period or amend the original KMD.
The safest correction starts with classification. A later return, cancellation or price reduction belongs to a traceable credit note and the current document period. An original invoicing or filing mistake belongs to the original KMD period. Related topic: VAT Registration in Estonia.
If a credit note crosses a VAT close or the seller and purchaser records no longer agree, send the original invoice, reason and settlement details through the Accounting Resources contact form before the next filing.