How Is an Invoice Claim Proved? Delivery Documents, Objections and Commercial Books

With Which Questions Does the Review of an Invoice Claim Begin?

An unpaid invoice is the starting document in investigating a claim. The outcome of the file, however, depends on the relationship that gave rise to the invoice, the performance agreed, the delivery or rendering of the service and the later steps. The first question is therefore not merely “Was an invoice issued?” Who agreed with whom, for what work; what price was agreed; how much of the work was done and what amount remains? These questions must be answered separately.

First the identity of the parties is determined. The business that placed the order, the company that issued the invoice, the person who used the delivery address and the company that made the payment may be different. That the trade names of companies in the same group resemble one another does not show that each is liable for the other’s debt. It must be shown that the person against whom the claim is directed is a party to the contract or is liable on some other legal ground. Matching the trade name in correspondence with the name registered in the trade registry is among the practical steps of this review.

The burden of proof is also assessed at the start of the file. The general rule is that the party who derives a legal consequence in its favor from an event must prove that event. The creditor must prove the events giving rise to the claim; a debtor who admits that the debt arose but says it has paid must explain the payment defense with its supporting evidence. However, statutory presumptions, events admitted by the parties and the nature of the defense raised may affect the burden of proof in the concrete file.[2]

What Are the Contract, Order, Invoice and Delivery Document For?

Commercial documents are often prepared for the same transaction, but they do not show the same fact. A quotation may state the price, an order may show a request for a certain quantity of product, a dispatch record may document the transport process. Issuing the invoice does not by itself prove that all these stages were completed. The review should focus on how the documents link to one another.[1][2]

The absence of a written contract does not in every case mean that no contract was formed. In relationships for which the law prescribes no special form, agreement of wills can come about in different ways. By contrast, the valid formation of a contract and the evidence by which it will be proved in court are separate matters. The HMK provisions on proof by written instrument, the value of the transaction and the exceptions that apply should be assessed separately.[2][3]

The invoice should also be distinguished from the collection document. Issuing an invoice does not by itself show that the price has been paid. If a document containing a payment statement or a commercial practice is involved, the content of the document, the signature and record system and the other evidence are examined together. Between “it has an invoice” and “it owes a debt”, and between “the invoice appears closed” and “payment was made”, there may be links that need to be explained in the file.[1][3]

How Is the Eight-Day Period for Objecting to an Invoice Assessed?

The start of the period and the scope of acceptance

Under TTK Article 21/2, a person who receives an invoice is deemed to have accepted its content if they do not object to the content within eight days from the date of receipt. It should not be assumed that the date the invoice was issued and the date it was received are the same. The date on which the invoice reached the addressee should be determined by the dispatch record, electronic system data or other suitable evidence.[1]

The effect of this rule is assessed within the ordinary content of the invoice and the relationship on which it rests. Failure to object does not in every case create a contract that was never formed; it does not turn goods that were not delivered into delivered goods. Price, quantity, performance, payment and contract terms added later cannot be reduced to the same legal problem. Especially where the underlying relationship or the delivery is denied, the creditor’s evidence on that point matters separately.[1][6]

A person who objects within the period should also not be content with merely saying “I owe nothing.” The invoice, the item and the reason to which the objection is directed should be explained; the part accepted as correct and the part in dispute should be separated. For example, a wrong unit price, incomplete delivery, a service never rendered and an earlier payment require different explanations. As much as the content of the objection, the record showing that it reached the addressee should be preserved.

What does a decision in which delivery was not proved show?

In the decision of the 11th Civil Chamber of the Court of Cassation (Yargıtay 11. Hukuk Dairesi) of June 3, 2025, E.2024/6090, K.2025/3953, the contractual relationship and the delivery of goods were discussed in an enforcement proceeding based on two invoices. The invoices had been issued by the creditor, but sufficient documents confirming the delivery process could not be produced. The other side’s records and the tax records brought into the file also did not confirm the alleged sale. The judgment dismissing the claim on the ground that the claim was not proved was upheld.[6]

This decision does not show that every invoice dispute will end in the same way. The practical conclusion that can be drawn is that the invoice’s reaching the other side and the performance of the obligation to which the invoice relates must be explained separately in the file. Nor should the lapse of eight days be interpreted to mean that all defenses fall away in every circumstance.

How Are the System Record, Rejection and Notification of Objection Distinguished in an E-Invoice?

The electronic flow and the legal dispute are not the same review

The e-invoice’s reaching the recipient’s system, its processing for tax and document-order purposes, the giving of an application response in a commercial scenario and the receipt of the goods to which the invoice relates are different events. When a file says “accepted”, it should be explained which act is meant. The technical transmission record, a declaration of intent directed at the content and actual delivery should not be used in place of one another.[1][4]

The Revenue Administration (GİB) e-Invoice Cancellation, Warning/Objection Notification Guide regulates separately the rejection application response and external objection routes in the commercial invoice scenario, and the relevant cancellation and notification processes in the other scenarios. The act that can be used must therefore be determined according to the scenario of the invoice and the stage reached. In particular, an objection notification made through the portal is treated in the guide as the notification to the system of an objection previously made externally. The actual objection and this notification should not be thought of as a single act.[4]

Which records should be kept together?

In the review, the invoice’s unique document number, the original electronic file, dispatch and delivery information, any application response, the cancellation request, the objection document and the record of its reaching the addressee should be handled together. An act in the system or the other side’s response should not be presented, torn from the other evidence, as a result that conclusively determines the existence or non-existence of the debt.[2][4]

A screenshot can make the record easier to understand. However, preserving the original electronic file, the relevant financial seal or signature data and the linked records is important so that the document can be verified afterwards. Relying only on a printed image of the invoice may make it harder to investigate the electronic process.[5]

How Are the Delivery of Goods and the Rendering of a Service Proved?

Person, place and quantity in the delivery chain

When a dispatch note is examined, it is not enough to look at whether there is a signature. The product, quantity, date, delivery address and the person receiving in the document are linked with the order. The meaning in the contract of delivery to the carrier and delivery to the buyer should also be determined. The provision on where delivery will take place, the transport record and actual practice can lead to different results.[2][3]

Where the person receiving is a company employee, a warehouse worker, a subcontractor or staff of another business, their connection with the transaction is investigated. Just as it cannot be said that every delivery document must bear the signature of the company’s registered representative, a signature put by just anyone cannot be attributed to the company without investigation. The method used in earlier deliveries, a letter of assignment, the warehouse entry record and the parties’ correspondence can explain this connection.

Denying a signature and objecting to the quantity delivered are also different. If the debtor claims that the signature on the document does not belong to them or to the person concerned, a review suited to this is needed. If the signature is accepted and the quantity is disputed, packaging, weighing, counting, an incomplete-delivery record and later notifications become important. Explaining to which event the objections are directed reduces unnecessary examinations.[2]

Indicators of performance in services

In service claims there may be no physical delivery document. Depending on the nature of the work, a work report, maintenance form, installation record, access log, approved output or correspondence on a completed stage may be used. These records should show which part of the work undertaken in the contract was performed. Staff merely having worked and the result promised in the contract having been achieved do not mean the same thing in every contract.

Defenses of no performance, incomplete performance and defective performance are also assessed separately. Notification of defects and inspection duties may vary according to the type of contract and the situation of the parties. The eight-day period prescribed for objecting to an invoice should not be used as the only period applicable to all delivery and defect disputes.[1][3]

Under What Conditions Do Commercial Books Constitute Evidence?

Distinguishing an accounting printout from a commercial book

HMK Article 222 makes the evidentiary character of commercial books in commercial cases subject to special conditions. Being kept in accordance with the law and completely, the necessary certifications having been made and the entries corroborating one another are parts of this review. For electronic books, the relevant electronic record and certification system is taken into account. A current-account statement taken from an accounting program is not regarded as a commercial book that fulfills all these conditions merely because its heading says “account statement.”[2]

That a book is properly kept also does not mean that each entry in it is to be accepted as conclusively true on its own. The other party’s books, the basis of the entries and evidence to the contrary are examined. The law also has limits on separating entries for and against a person. Ignoring a payment or return entry in the same book while asserting a claim entry does not produce a sound assessment.[2]

Failure to produce a book versus the absence of an entry in the book

The provision of HMK Article 222/3 as amended by Law No. 7251 specifically distinguishes these two situations. If there is no entry at all on the matter in the other party’s properly kept commercial books, the book owner’s own entries cannot be used in its favor within the scope of this provision. This does not mean that the claim cannot be proved by any evidence or that it ends automatically; the value of the other evidence is examined separately.[2]

The other party’s failure to produce its books is different. A proper request for production, the court’s interim decision, the notification and the content of the warning are assessed together with the other conditions in the law. The general conclusion “the other side did not bring its books, so all my allegations are proved” is not correct. The production provisions in HMK Articles 219–222 and, in particular, the conditions of the situation in which the other party’s books are relied on should not be confused.[2]

A decision in which there were records supporting the invoice

In the decision of the 11th Civil Chamber of the Court of Cassation of May 11, 2026, E.2025/6050, K.2026/2842, an invoice claim arising from the sale of flour was examined. The creditor’s properly kept books, the other side’s failure to produce its books despite a proper warning, and tax declarations for the relevant transaction period confirming the invoices were assessed together. The claim was accepted; the judgment, as corrected on appeal with respect to interest, was upheld by the Court of Cassation.[7]

The difference between this file and the earlier decision in which delivery was not proved lies in the totality the documents formed. In addition, the Ba/Bs records in the decision relate to past transaction periods. GİB has announced that the Ba/Bs reporting obligation was abolished for September 2024 and later periods under Tax Procedure Law General Communiqué Serial No. 565. A record used in old decisions should not be presented as a mandatory declaration to be requested from every business today.[7][8]

How Are E-mails, Messages and Other Digital Records Assessed?

HMK Article 199 accepts data in electronic form within the scope of documents. However, being counted as a “document” does not mean that every type of record is sufficient evidence on its own for every transaction. The rule of proof by written instrument, the commencement of proof and the statutory exceptions must be taken into account. In particular, showing that a message came from the other side or its representative and makes the asserted transaction probable may matter under HMK Article 202.[2]

Only the sentence that appears favorable in the correspondence should not be taken. What came before and after the message, its attachments, sender information, date and time, the relevant order number and terms changed later should be preserved together. Does the expression “OK” relate to acceptance of the price, to the delivery address or to the meeting time? Without seeing the context of the text, no sound conclusion can be drawn.

When the source and integrity of records are disputed, the original file, e-mail headers, system logs and necessary technical examination may come onto the agenda. Content obtained by unauthorized access to another person’s account and a business’s own transaction records to which it has lawful access are not in the same position. The limit in HMK Article 189/2 on the use of unlawfully obtained evidence must be observed.[2]

If a record held by a third party or by the other side is needed, the document and the reason for requesting it should be made concrete and the appropriate procedure followed. For evidence at risk of being lost or later becoming impossible to examine, preservation of evidence may be assessed separately. For each request for records, instead of asking for unlimited access to all company data, the documents shown to be connected with the dispute should be identified.[2]

How Are Payment, Return and Balance Calculated Together?

Which invoice does the payment relate to?

In relationships with more than one invoice, looking at the total bank movement may not be sufficient. The payment’s date, sender, recipient, description and the debt to which it relates are examined. TBK Articles 100–102 regulate the relationship of partial payment to interest and expenses, the statement made where there are several debts, and the rules that apply when no statement is made. Therefore, not every payment can be deducted from the invoice automatically selected by the accounting program.[3]

Giving a payment instruction should be distinguished from the money’s reaching the relevant account. A transfer instruction that was cancelled or did not go through should not be booked as a completed payment. The connection with the debt of a payment made by another company or a third person should likewise be established by the description, correspondence and the parties’ records. The same payment should not be deducted a second time, either invoice by invoice or in the total account.

A partial payment may be a meaningful fact in the file; but it is not necessarily treated as acceptance of the whole invoice price and of every condition. What matters is which debt it was made for and with what description. The debtor may have objected to a particular item and paid another. In the balance calculation prepared by the creditor, this distinction should be visible.

Return, offsetting (mahsup) and set-off (takas)

Issuing a return invoice does not by itself show in every case that the goods were actually returned or that the other party accepted the return. The returned product, quantity, date, the person receiving and the contractual basis of the return are investigated. Because price reduction, cancellation and physical return are separate transactions, the records should be matched accordingly.[1][2]

Offsetting (mahsup) may mean, for example, deducting a payment made or a discount accepted from the same claim account. Set-off (takas), by contrast, is a separate legal act aimed at extinguishing reciprocal claims under statutory conditions; the conditions from TBK Article 139 onwards and the declaration of set-off are examined. A damage claim raised by the debtor should not be regarded as automatically deducted from the invoice.[3]

The term “current account” (cari hesap) should also be used with care. That transactions are tracked in a customer account in accounting does not by itself show that there is a written current account contract within the meaning of TTK Article 89. It should be explained whether the claim in suit rests on the individual invoices or on the balance of a legally established current account. This distinction can affect the assessment of the claim’s enforceability.[1]

How Are Documents Matched in a Hypothetical File?

The example below does not describe any real file. Suppose a business ordered one hundred units of a product, the seller issued an invoice for all of them, the buyer claims to have received eighty units and to have returned ten of them. Suppose also that there is a bank transfer with only “payment” in its description. In this case, assessing on the basis of a single total figure makes the different parts of the dispute invisible.

At the end of the review it may be seen that not all items are disputed to the same extent. The order may have been accepted while only the quantity delivered is disputed. There may be agreement on the payment while the validity of the return is debated. Showing each item separately makes both the petition and the defense concrete and identifies the real area of dispute in negotiations.[2]

How Are the Due Date, Interest and Other Terms on the Invoice Reviewed?

A late-payment charge, a penalty clause or a new payment condition added unilaterally at the foot of the invoice does not in every case become a contract term merely because the invoice was not objected to. It should be investigated whether such a claim has a basis in the contract, in a later agreement between the parties or in some other applicable legal ground. The rule on acceptance of the invoice content should not be treated as an authority to alter all the terms of the contract unilaterally.[1][3]

The date on the invoice and the date on which the debt fell due may also differ. Payment may have been tied to a certain date after delivery or to an act of acceptance. As to default, the general rule in TBK Article 117 and any special provisions apply. No single result can be reached that a separate warning is needed for each invoice, or that each invoice automatically causes default on the day it is issued.[3]

In calculating interest, the legal basis, the starting date, the periods and the payments made should be shown clearly. Carrying over to a new file the rate applied in an old decision is not appropriate. Indeed, in the decision of May 11, 2026, although the existence of the claim was accepted, the wrong application of the interest rate for the enforcement period was separately corrected. Proving the claim and correctly calculating additional claims require independent review.[7]

Which Questions Should Be Answered in an Expert Examination?

The usefulness of an expert examination depends on correctly identifying the technical and calculation questions in the file. A general question such as “Is there a claim?” alone may not sufficiently separate the disputes between the parties. It should be shown which invoice is tied to which order and delivery record, from which transaction the difference between the books arises, which payment was deducted and for what reason, and how the return calculation was made.

Under HMK Article 266, the expert examines matters requiring special or technical knowledge; the legal assessment belongs to the court. A claim appearing in the accounting records and the existence of a legally enforceable claim are not the same assessment. It should be clear on which documents and acceptances the amount found by calculation in the report rests.[2]

The party reviewing the report should also make its objection concrete. An omitted payment, a wrongly matched invoice, an illegible delivery document or an unexplained book difference should be stated under separate headings. Instead of objecting to the entire report merely because the outcome is not favorable, an explanation showing the effect of the error on the calculation is more useful. With regard to time limits and the rules on submitting evidence, it should be requested by which step the incomplete examination is to be remedied.[2]

What Preparations Should Be Made Before Enforcement or Litigation?

The route to be followed and time limits

Not every dispute based on an invoice is a commercial case merely because there is an invoice. The court with subject-matter jurisdiction is determined by examining the capacity of the parties, the nature of the work and the special provisions of the law. For monetary claims in the nature of commercial cases and related claims, mediation as a condition precedent to litigation under TTK Article 5/A is assessed. This provision lists, in addition to claims and compensation, actions for annulment of objection, actions for negative declaratory judgment and actions for restitution.[1]

The document conditions and time limits of enforcement proceedings, a direct claim action and the routes available after an objection to the enforcement are not the same. In particular, the difference between annulment of objection and lifting of objection should be assessed together with the documents at hand. A single limitation period valid in every case should likewise not be assumed for an invoice; the period is determined according to the underlying relationship and the nature of the claim.[3]

For the creditor, collection of a claim through enforcement and litigation, and for the debtor, negative declaratory action and restitution, answer different legal needs. If the statement of claim has been served, the response period and the preparation of evidence should be addressed separately. The continuation of commercial talks should not lead to the assumption that procedural time limits stop automatically.

Making the file suitable for decision-making

Preparing a document list before applying is useful. Against each invoice, the link to the order, the delivery or service record, the objection, the return and the payment is written. A missing document is not left merely by naming it; from whom it can be obtained, for which event it is needed and its effect on the existing evidence are explained. The records that weaken the claim should be examined as much as the documents that seem favorable.

A short event chart may be added to this list. The order date, the date of change, the dispatch and delivery dates, the receipt of the invoice, the objection, the return and the payment dates are tracked in separate columns. In this way the connection of an advance paid before the invoice with a document issued later, or a quantity difference that emerged after delivery, can be seen. If there are many transactions on the same day, the document number and the product code matter as much as the date. Reference to the same document under different names in the file should be avoided; the relationship between the first version of a cancelled or corrected document and its later version should be preserved.

For the debtor, too, preparation does not rest only on pointing out deficiencies in the creditor’s file. If it is claimed that payment was made, that the product was returned or that the price was changed afterwards, the basis of these explanations should be identified in good time. The person concerned having left the company, the old e-mail address having been closed or the warehouse system having been renewed can make it harder to reach the document. It is therefore useful to preserve existing records in a lawful manner and to determine what information the persons who know the transaction can provide. When creditor and debtor each build the same event chart separately from their own records, the source of the dispute can be seen more easily.

In the final assessment, the amount of the dispute, difficulties of proof, expected expenses, the debtor’s payment position and the likelihood of agreement are considered together. A settlement can be assessed by determining on which items the parties can agree and how the payment plan will be implemented. Reaching a court judgment and actually collecting the price are separate stages; the preparation must take both into account.

Conclusion

Assessing an invoice claim requires linking all transactions from the contract to the remaining balance. The period for objecting to an invoice, proof of delivery, the value of commercial books and the reliability of electronic records are separate questions. When these questions are examined without being reduced to the existence of a single document, the strong and weak aspects of the claim and the defense are seen more clearly.

Careful work includes matching each allegation with the relevant document, assessing the counter-objection, explaining calculation differences and determining the appropriate procedural route. A file prepared in this way makes it understandable what amount the company can claim on what grounds, or to which debt it objects and why. The outcome of the dispute is determined in line with the characteristics of the concrete case and the evidence assessed together.

Frequently Asked Questions

Does an invoice alone prove the claim?

Such a conclusion cannot be stated for every file. The contract on which the invoice rests, delivery or service, the parties’ acceptances and objections and the other records are examined. Especially where the underlying relationship or the delivery is denied, the evidence supporting the invoice becomes important.[1][2][6]

If there is no objection to the invoice within eight days, are all rights lost?

No. The scope of the acceptance of content under TTK Article 21/2 is assessed separately from the existence of the contract, performance, payment and terms added later. Letting the period lapse is not insignificant; but it does not mean that all defenses fall away in every case.[1][6]

Is it enough to keep the PDF printout of an e-invoice?

A PDF image can make review easier; but preserving the original electronic file, the verification data and the related system records is important. When the source or integrity of the document is disputed, there may be points that cannot be explained from the image file alone.[2][5]

If there is no invoice entry in the other party’s book, does the claim end?

No. The absence of the relevant entry in the properly kept book of the other side affects, under HMK Article 222/3, the creditor’s use of its own books in its favor. This is not the same as the possibility of proof by other evidence or as the claim’s ceasing automatically.[2]

Does issuing a return invoice automatically reduce the debt?

By itself, it does not in every case. The legal basis of the return, the return of the products, the other side’s statement and the integrity of the records are examined. Actual return should be distinguished from price reduction or cancellation of the transaction.[1][2]

Does a partial payment show that the whole invoice was accepted?

Not always. The debt for which the payment was made, its description and any reservations are examined. If there are several debts, the debt to which the payment will be applied is determined within the framework of TBK Articles 100–102 and the concrete records.[3]

If the creditor’s books are in proper form, is the case certainly won?

No. In addition to the form of the books, the position of opposing entries, production procedures and evidence to the contrary are assessed. Jurisdiction, conditions of suit, time limits and the legal basis of the claim are also examined. The suitability of a single document alone does not guarantee the outcome of the case or of collection.[1][2]

Sources

1. Law No. 6102, Turkish Commercial Code (Türk Ticaret Kanunu). Arts. 4–5, 5/A, 18/3, 21, 23, 89
2. Law No. 6100 on Civil Procedure (Hukuk Muhakemeleri Kanunu). Arts. 189–190, 194, 199–203, 219–222, 266, 279–282, 400 et seq.
3. Law No. 6098, Turkish Code of Obligations (Türk Borçlar Kanunu). Arts. 1, 12, 100–103, 117, 139–145, 146–147
4. Revenue Administration (Gelir İdaresi Başkanlığı) — e-Invoice Application Cancellation, Warning/Objection Notification Guide, Version 1.2. January 2025; in particular pp. 4–6 and the cancellation/objection explanations by scenario
5. Revenue Administration (Gelir İdaresi Başkanlığı) — e-Invoice Application Retention Guide, Version 1.1. September 2013; section 3, p. 7, original format and electronic verification elements
6. 11th Civil Chamber of the Court of Cassation (Yargıtay 11. Hukuk Dairesi), June 3, 2025, E.2024/6090, K.2025/3953. Failure to prove the underlying relationship and delivery in an action for annulment of objection based on an invoice; dismissal upheld
7. 11th Civil Chamber of the Court of Cassation (Yargıtay 11. Hukuk Dairesi), May 11, 2026, E.2025/6050, K.2026/2842. Invoice claim, properly kept books, failure to produce books despite a proper warning, reciprocal tax declarations for an earlier period and interest calculation
8. Revenue Administration (Gelir İdaresi Başkanlığı) — announcement of Tax Procedure Law General Communiqué Serial No. 565 (565 Sıra No.lu Vergi Usul Kanunu Genel Tebliği). September 25, 2024; abolition of the Ba/Bs reporting obligation for September 2024 and later periods