Foreign founders in Türkiye often price in dollars or euros. The invoice is issued in foreign currency, the customer pays the same amount in foreign currency a few weeks later, and commercially the account is settled. In the statutory books it is not: they are kept in Turkish lira, and the lira value of the invoice and of the payment differ. Turkish practice closes that difference with a separate invoice, the kur farkı faturası (exchange rate difference invoice).

Which exchange rate applies

Türkiye has a floating exchange rate regime, so the rate on the sale date and the rate on the collection date are usually different.

• If the contract between the parties fixes an exchange rate, the contractual rate applies.
• If no rate is agreed, use the Central Bank of the Republic of Türkiye (TCMB) buying rate published in the Official Gazette (Resmî Gazete) on the invoice date.
• If no rate is published for that day (public holidays, weekends, half working days), use the buying rate published on the last business day before it.

What the invoice is for

A foreign-currency invoice is entered in the statutory books in lira, with the foreign-currency amount shown alongside. Because time passes between issuing the invoice and collecting it, the lira amounts diverge. The invoice issued for exactly that difference is the kur farkı faturası.

A worked example

• 3 October 2025: Company A invoices customer B for USD 100 including VAT. Rate 41.90, so TRY 4,190 in the books.
• 28 October 2025: B pays USD 100. Rate 41.93, so TRY 4,193.
• Foreign-currency balance: zero. Lira balance: TRY 3.

To close the lira balance, Company A issues customer B an exchange rate difference invoice for TRY 3 including VAT. The same TRY 3 should also appear in B’s statutory records.

Who issues it: seller or buyer

The party left with a lira balance in its favour issues the invoice.

• The rate rose after the invoice: the seller collected more lira than it invoiced, so the seller issues the invoice to the customer.
• The rate fell after the invoice: the lira paid is below the lira invoiced, so the customer issues the invoice to the seller.

What must be on the invoice

• It is issued in Turkish lira. It cannot be issued in foreign currency: the foreign-currency balance is already zero, and only the lira balance needs closing.
• VAT is calculated on the exchange rate difference.
• The description must state that it is an exchange rate difference invoice (“Kur farkı faturası”). You may add details of the original invoice, such as its date and amount, but that is optional.
• The format follows your normal invoicing: paper if you invoice on paper, e-invoice (e-fatura) if you invoice electronically. If the counterparty is an e-fatura taxpayer, it must be an e-invoice.

VAT: the rate and the calculation

The VAT rate is the one that applied to the goods or services on the original invoice.

• Original invoice at 20%: exchange rate difference invoice at 20%.
• At 10%: 10%. At 1%: 1%.
• VAT-exempt under an incentive: no VAT.
• Subject to VAT withholding (tevkifat): VAT withholding applies as well.

The lira balance is treated as a VAT-inclusive amount, and VAT is worked out backwards from it. If the remaining balance is TRY 120 and the rate is 20%, the invoice shows a base of TRY 100, VAT of TRY 20 and a total of TRY 120.

When to issue it

When the payment is collected and the earlier foreign-currency invoice is closed in full or in part.

For payments by cheque, the relevant date is when the cheque is actually paid into cash or the bank. The date the cheque was written or handed over is not enough.

Is it mandatory, and what is the penalty

Yes. Adjusting the collection rate to match the invoice rate so that the lira balance shows zero is not correct.

If the lira balance is cleared without the invoice, the special irregularity penalty (özel usulsüzlük cezası) is 10% of the amount that should have been invoiced, for each invoice not issued. According to the source, it can be imposed on both parties: the one that should have issued the invoice and the one that should have received it.

When no invoice is needed

• Period-end valuation. At period end, foreign-currency receivables and payables are revalued at the Central Bank rates, and the differences go to exchange gain or loss accounts. No invoice is issued for these. An invoice requires a lira difference arising from an actual payment.
• Companies abroad. The invoice is issued only between companies in Türkiye. For foreign-currency sales to or purchases from abroad, the remaining lira balance is closed through exchange gain or loss accounts.

Transactions indexed to a foreign currency are not an exception: if a lira balance remains after payment, it is closed with an exchange rate difference invoice in the same way.

Does the invoice have to be paid

The author of the source, a certified public accountant, notes that this is his own interpretation: these invoices are not paid, because they are adjusting documents that close the lira balance of the account. The issuer pays the VAT shown on the invoice to the tax office for that month, and the counterparty deducts it in its own VAT return.

Checklist for a foreign founder

• Check whether your contracts with Turkish customers and suppliers fix an exchange rate.
• After each foreign-currency collection, ask your accountant whether a lira balance remains on the account.
• Remember that you may be on the receiving side: if the rate fell, your customer invoices you.
• Do not zero the balance by hand.

Source

Yusuf Şahin, SMMM (certified public accountant), “Kur farkı faturası” Q&A, Paraşüt blog: parasut.com/yazar/yusuf-sahin. The example rates and dates are taken from the source.

This material is for information only and is not tax or legal advice. Confirm how the rules apply to your company with your accountant (mali müşavir).