Corporate & Commercial
Invoices, the Eight-Day Objection Rule and Commercial Books as Evidence in Turkish B2B Disputes (TTK Arts. 18 & 21; HMK Art. 222)
Two provisions decide a surprising share of Turkish commercial claims before anyone reaches the merits: the eight-day period in which a merchant must object to an invoice, and the strict conditions on which commercial books may be used as evidence. Foreign companies lose winnable cases by treating both as formalities.
A Turkish supplier issues an invoice. The buyer reads it, disagrees with a line, decides to raise it at the next meeting, and files the document. Nine days later, without anything further happening, the buyer's legal position has quietly changed. Under Article 21(2) of the Turkish Commercial Code (Türk Ticaret Kanunu, TTK No. 6102), a person who receives an invoice and does not object to its content within eight days of receipt is deemed to have accepted that content.
The corresponding trap sits on the other side of the file. A creditor confident that "our books show the debt" arrives at a hearing to discover that Article 222 of the Code of Civil Procedure (Hukuk Muhakemeleri Kanunu, HMK No. 6100) imposes cumulative conditions before commercial books count as evidence at all — and that books which fail those conditions do not merely become neutral. They become evidence against their own owner.
1. What TTK Article 21 Actually Says — and What It Does Not
Article 21 is short, and its precision is the reason it is so often over-read.
Paragraph 1 creates an entitlement rather than an obligation: a merchant who, in the context of their commercial enterprise, has sold goods, produced goods, performed work or provided a benefit may be required by the other party to issue an invoice, and to show the price in the invoice if it has been paid.
Paragraph 2 contains the rule that decides cases: a person who receives an invoice is deemed to have accepted its content if they have not raised an objection to that content within eight days of the date of receipt.
Read the verb carefully. The statute says the recipient is deemed to have accepted the content (kabul etmiş sayılır). It does not say that the debt is thereby created, that the claim is proved, or that the recipient loses every defence. The distinction is not academic:
- The presumption operates on the content of the invoice — the description, the quantities, the unit prices, the terms stated on the document.
- It does not manufacture an underlying relationship. An invoice sent to a party with whom no contract exists does not create one by the passage of eight days.
- It shifts the practical burden. After eight days of silence, the recipient who wants to dispute the content is arguing against a statutory presumption instead of putting the issuer to proof.
Paragraph 3 extends the same logic to confirmation letters. A person who receives a writing confirming the content of statements made under contracts concluded by telephone, telegraph, any means of communication or information technology, by any other technical means, or orally, is deemed to have accepted that the confirmation letter conforms to the contract or the statements made, if they have not objected within eight days of receipt. In an era of contracts concluded on messaging platforms and confirmed by a follow-up email, this is the more dangerous of the two paragraphs, and the less well known.
2. The Eight Days: When They Start and How to Use Them
The period runs from the date of receipt, which places a premium on being able to prove when the document arrived. Three practical rules follow.
Record receipt as a business process, not as a legal reflex. Where invoices arrive by e-mail into a shared mailbox, the date the document entered the organisation should be recorded automatically. Disputes about the start of the eight days are usually resolved on the issuer's transmission evidence, which the recipient does not control.
Object to content, not to payment. An objection that says "we are not paying until the other matter is resolved" is a statement about payment. An objection that says "the quantity invoiced is 400 units; 220 were delivered on 3 September and the balance was never delivered" is an objection to the content. Only the second engages Article 21(2).
Object once, in writing, to the issuer. The statute does not prescribe a form for the objection itself, but a dispute in which the objection cannot be produced is, evidentially, a dispute in which no objection was made.
3. Where Form Is Prescribed: TTK Article 18(3)
Article 18 does prescribe a form, but for a narrower and frequently misunderstood category of communications. Under Article 18(3), notices or warnings between merchants relating to placing the other party in default, to terminating the contract, or to withdrawing from the contract are made through a notary, by registered letter, by telegram, or by registered electronic mail using a secure electronic signature.
Two errors recur, and they run in opposite directions:
- Over-application. "Every notice between merchants must go through a notary" is wrong. The formality attaches to those three specific acts. An objection to an invoice under Article 21(2) is not one of them, and a written objection sent by ordinary means is not invalid for want of notarial form.
- Under-application. A supplier that terminates a distribution agreement by e-mail, or purports to place a Turkish counterparty in default by a message on a messaging platform, has not complied with Article 18(3) — and the consequences surface later, when the date of default determines the interest calculation or the validity of the termination.
Article 18 also frames the standard against which merchant conduct is judged: paragraph 2 requires every merchant to act like a prudent businessperson in all activities relating to their trade. That standard is what makes "we did not read the invoice" a weak position in a commercial court.
4. Commercial Books as Evidence: The Cumulative Conditions of HMK Article 222
Turkish courts do treat commercial books as evidence — but only books that satisfy a set of conditions that are cumulative, not indicative.
Paragraph 1. In commercial cases the court may order the production of the parties' commercial books, of its own motion or on the application of one of the parties.
Paragraph 2 — the gateway. For commercial books to be accepted as evidence in commercial cases, it is a condition that they have been kept completely and in accordance with the law and proper procedure, that their opening and closing approvals have been obtained, and that the book entries confirm one another.
The closing approval (kapanış onayı) is the condition most often missing in practice, particularly for foreign-owned Turkish subsidiaries whose accounting is managed remotely. Its absence is not a technicality; it removes the books from the category of admissible evidence in favour of their owner altogether.
Paragraph 3 — evidence in your own favour. For entries in books kept in accordance with paragraph 2 to be accepted as evidence in favour of their owner and the owner's successors, it is necessary that the entries in the other party's books kept in accordance with the same conditions are not contrary to them, or that the other party does not produce its commercial books, or that the opposite of the entries has not been proved by deed or other conclusive evidence. A sentence added in 2020 closes a gap: where the other party's books, kept in accordance with the conditions in paragraph 2, contain no entry at all on the relevant matter, the commercial books cannot be used as evidence in favour of their owner. The paragraph ends with a rule that cannot be worked around: entries in favour of and against the owner in books kept in accordance with these conditions cannot be separated from one another.
Paragraph 4 — the sting. Entries in commercial books which lack opening or closing approvals and whose entries do not confirm one another are evidence against their owner. Defective bookkeeping is therefore worse than no bookkeeping at all: the books remain usable by the opponent while being unusable by their owner.
Paragraph 5 — the non-merchant's lever. Even where one of the parties is not a merchant, if that party states that it will accept the entries in the merchant's commercial books but the opposing party refrains from producing its books, the party requesting production is deemed to have proved its claim.
5. How the Two Provisions Interact in a Real File
Neither provision is decisive alone; the outcome usually turns on how they combine.
| Scenario | TTK Art. 21 position | HMK Art. 222 position | Practical effect |
|---|---|---|---|
| Invoice received, no objection in 8 days; both parties' books compliant and consistent | Content deemed accepted | Creditor's books usable in its favour | Strong creditor position; dispute shifts to defences outside the invoice content |
| Invoice received, no objection; creditor's books lack a closing approval | Content deemed accepted | Creditor's books are evidence against the creditor under para. 4 | The presumption survives, but the creditor's own accounting can be used against it |
| Timely written objection to content; debtor's books compliant and silent on the item | No deemed acceptance | Creditor's books cannot be used in its favour where the debtor's compliant books contain no entry | Creditor must prove the underlying relationship by contract, delivery and correspondence |
| Debtor refuses to produce books after being ordered to | Depends on objection | Non-production is one of the alternatives in para. 3; para. 5 applies where the counterparty is not a merchant | Refusal is frequently worse for the debtor than production would have been |
| Termination or default notice sent by e-mail only | Not affected by Art. 21 | Not affected by Art. 222 | Art. 18(3) formality problem: the date of default or the validity of termination is exposed |
The pattern is consistent. The invoice presumption governs the content of the claim; the books govern who can prove what; and Article 18(3) governs the acts that change the parties' legal positions. A file that is strong on one and careless on the others is not a strong file.
6. A Practical Protocol for Foreign Companies
Six habits eliminate most of the exposure created by these provisions.
- Date-stamp every incoming invoice on arrival, automatically, and route it to a named owner. The eight-day period does not pause for internal approval workflows or for annual leave.
- Use a standing objection template that describes the disputed content specifically — quantity, delivery date, unit price, scope — rather than announcing a payment position.
- Treat confirmation e-mails as documents with a deadline. Article 21(3) applies the same eight days to writings confirming contracts concluded by telephone, messaging, or orally.
- Verify the opening and closing approvals of your Turkish entity's books every year, and keep proof. This single check determines whether your accounting can be used in your favour under Article 222(2).
- Reserve notarial, registered-post, telegram or registered electronic mail form for the three acts named in Article 18(3): default, termination and withdrawal. Do not use it for everything, and never omit it for those.
- Assume the file will be read by an expert. In practice a court-appointed accounting expert reconciles the books of both sides; consistency between your ledger, your invoices and your delivery records is what survives that review.
None of this is exotic Turkish practice. It is the ordinary discipline of trading under a code that attaches real consequences to short deadlines and to bookkeeping formalities — and that rewards the party who treated both as operational matters rather than as legal afterthoughts.
Frequently Asked Questions
If we miss the eight days, have we lost the case?
No. TTK Article 21(2) provides that a person who receives an invoice and does not object to its content within eight days of receipt is deemed to have accepted that content. That is a presumption about the content of the document, not a judgment on the underlying relationship. It does not create a contract that never existed, and it does not extinguish defences that lie outside the invoice content, such as payment, set-off, or the absence of any dealing between the parties. What it does is shift the practical burden onto the recipient.
Does our objection have to go through a notary?
Not for an invoice objection. The formality in TTK Article 18(3) applies to notices or warnings between merchants relating to placing the other party in default, terminating the contract, or withdrawing from the contract, and requires the notary, registered letter, telegram, or registered electronic mail with a secure electronic signature. An objection to the content of an invoice is not one of those acts. It should nonetheless be in writing and provable, because an objection that cannot be produced has no evidential existence.
Our Turkish subsidiary's books have no closing approval. Does that matter?
It matters more than most clients expect. HMK Article 222(2) makes it a condition of admissibility that commercial books have been kept completely and in accordance with the law and proper procedure, that their opening and closing approvals have been obtained, and that the entries confirm one another. Article 222(4) goes further: entries in books lacking opening or closing approvals, whose entries do not confirm one another, are evidence against their owner. Defective books are therefore usable by your opponent and unusable by you.
Can we rely on our own books to prove the debt?
Only within the conditions of HMK Article 222(3). Entries in compliant books may be accepted as evidence in favour of their owner where the other party's books kept to the same standard are not contrary to them, or where the other party does not produce its books, or where the opposite has not been proved by deed or other conclusive evidence. Since 2020 the provision adds that if the other party's compliant books contain no entry at all on the relevant matter, your books cannot be used in your favour. And favourable and unfavourable entries cannot be separated from one another.
What happens if the other side refuses to produce its books?
Refusal is one of the alternatives that allows compliant books to be used in favour of their owner under Article 222(3). Article 222(5) goes further in a specific configuration: where one party is not a merchant but states that it will accept the entries in the merchant's books, and the merchant then refrains from producing them, the party requesting production is deemed to have proved its claim. Non-production is therefore rarely a safe tactic.
Does the eight-day rule apply to e-mails confirming a deal agreed by phone?
Yes, and this is the paragraph most often overlooked. TTK Article 21(3) provides that a person who receives a writing confirming the content of statements made under contracts concluded by telephone, telegraph, any means of communication or information technology, by any other technical means, or orally, is deemed to have accepted that the confirmation letter conforms to the contract or the statements, if no objection is raised within eight days of receipt.
We are the supplier. What single step most improves our position?
Being able to prove the date the invoice was received, and keeping books that satisfy HMK Article 222(2). The first activates the presumption in TTK Article 21(2) on a date you can demonstrate; the second determines whether your own accounting can be used in your favour at all. Delivery evidence tied to each invoice line is the third element, because it answers the defences that survive the presumption.