Acceptance certificates (акти) without the customer’s signature: how to rebuild document workflow after 1 квітня 2026 року

Starting April 1, 2026, a contractor will have the right to record a completion certificate in their accounting records that the client has not signed. This possibility was introduced by Law No. 4791-IX, which added a single paragraph to Part 2 of Article 9 of the Law on Accounting. The business community reacted immediately: contracts now include clauses about unilateral certificates, and invoices with the details of a source document, invoice-acts, and combined forms are entering circulation.

It looks like a simplification. In reality, a company that forgoes bilateral signatures is transitioning to a different document workflow model, and this model requires a much stronger contract.

What exactly did Law No. 4791-IX permit?

The new paragraph in Part 2 of Article 9 of the Law on Accounting is worded as follows:

"If a source document contains information about the date (period) of service provision, work performance, or lease (rental), the absence of the details required by paragraphs six and seven of this part from the client (for services/works) or the lessee (tenant) does not constitute a violation of the requirements for preparing a source document, provided that such a procedure for documenting business transactions is stipulated in a written contract, and such business transactions are reflected in the accounting records during the period they are carried out."

A comment on this provision: the simplification only works if three conditions are met simultaneously. The document contains the date or period of service provision. The written contract explicitly provides for this documentation procedure. The transaction is reflected in the accounting records in the period it occurred. The contractor's details remain fully mandatory; the relaxation only applies to the client or lessee.

The new rules do not apply to transactions involving public funds or construction contracts.

Why a signed certificate was never a complete safeguard

The tax authorities have challenged the reality of transactions even when a certificate bears both signatures. A bilateral certificate does not confirm the quality of services and does not protect against future disputes. Its real value was different: it was a simple, familiar mechanism for documenting agreements that also psychologically "closed" the transaction for the accountant and the manager.

Hence the power of inertia. It is roughly the same as with the abolition of mandatory company seals in its time.

Courts, by the way, accepted unilateral certificates even before these changes. In its ruling of September 4, 2023, in case No. 910/5352/21, the Supreme Court reasoned that a certificate signed by one party is valid if the other party fails to prove the validity of its refusal to sign. An unsigned certificate does not mean the transaction did not occur.

How businesses operate without completion certificates in the EU and the US

"In Europe, everyone works with invoices" is a common refrain in every discussion on this topic. This is true, but it's only half the truth. Behind the invoice stands an entire system that has developed over decades.

• EU. The basic transaction document is defined by Directive 2006/112/EC on VAT. An invoice, drawn up with all mandatory details, in itself grants the right to a VAT credit, and no member state can require additional documents for this purpose. A separate acceptance certificate is redundant in this structure.
• Acceptance by conduct. In EU, UK, and US contract law, the doctrine of "deemed acceptance" applies: if a client uses the results of the work or consumes a service and does not file a claim within the contractual period, a court considers the services accepted. This is why contracts there are so detailed: deadlines for objections, consequences of silence, communication procedures, etc., are all specified in advance.
• US. In public procurement, acceptance is recorded by the client themselves according to the procedure defined in the contract, and payment is made against an invoice within a 30-day period under the Prompt Payment Act. A separate bilateral certificate is absent from this system.
• Control is shifting to data. Italy processes every invoice through the state platform SdI, and the document is invalid without it. Since 2024, Romania has required invoices to be submitted via e-Factura. Belgium launched mandatory B2B e-invoicing in January 2026, and Poland is implementing KSeF. The tax authority sees the transaction the moment the document is issued, so it doesn't need a second signature.

Ukrainian businesses should take away not "an invoice instead of a certificate," but the interconnected system: a detailed contract, documented party conduct, and transaction visibility for the regulator.

What to include in your contract before switching to unilateral documents

Part 2 of Article 9 only requires a written contract with the relevant clause. Formally, this is sufficient. But in practice, a single clause will not protect you in a commercial dispute or during a tax audit. Do more:

Step 1. Add a direct clause to the contract: the completion certificate, bill, or invoice is issued unilaterally by the contractor; the client's signature is not mandatory.

Step 2. Describe the services specifically: composition, scope, result, and the procedure for agreeing on additional service volumes.

Step 3. Set a deadline for the client's comments and state that silence after this period expires signifies acceptance of the services.

Step 4. Define the channel for sending documents and the method for confirming their receipt: an electronic document management service or the addresses specified in the contract.

Step 5. Specify the procedure for filing claims and determining the cost if it depends on the actual volume.

Step 6. Duplicate the main clauses in the document itself. State in the invoice or unilateral certificate that payment confirms the absence of claims, and failure to submit comments within the established period signifies acceptance of services.

Don't rush with new and one-time counterparties. For a "casual" partner, a bilateral certificate is still the safest option. For long-term partners with established practices, the model without a second signature will work comfortably.

Unilateral certificate or invoice-act: which to choose

Choose a unilateral certificate if you are hesitant. The reason is simple: it is created after the services have been rendered or the work has been completed. An invoice is often issued in advance and does not reflect the final scope of work. This leads to three typical disputes: when the service was actually provided, when it was accepted, and what scope the parties agreed upon.

If you do work with an invoice that has the details of a source document (pervynnyi dokument), transfer the protective clauses directly into its text. This was already mentioned in Step 6.

Where forgoing a second signature creates risks

• Transactions involving public funds and construction contracts: there is a direct prohibition in the law.
• Corporate IT and complex long-term projects. Here, the outcome of a dispute is decided by documenting stages, completion, and the presence or absence of defects.
• Work for which practice requires additional documents: protocols, certificates of completion, result approvals.
• A counterparty with no history of cooperation.

When does the 'first event' for VAT occur with an invoice-act?

Let's take an example. On June 5, a contractor issued an invoice-act for services for the entire month of June, but the services themselves will continue until the end of the month. When did the supply occur? Won't the tax authorities interpret such a document as confirmation of services already rendered? There is no clear answer yet, and the most acute question is for continuous services: accounting outsourcing, IT support, subscription services.

In international trade, there's the added dimension of currency. If the date of supply, document issuance, or acceptance of performance "floats," the date for determining the exchange rate also changes. Consequently, so does the amount of exchange rate differences.

In the coming years, the approaches of accountants, auditors, lawyers, and regulatory bodies on these issues will diverge. Practice will be formed through individual consultations from the State Tax Service and the first tax audits.

Frequently Asked Questions

Have certificates of services rendered been abolished?

No. The source document remains mandatory for accounting but can have an arbitrary name. The law only removed the requirement for a second signature, and only if the parties have agreed to this in a written contract.

Is one clause in the contract about unilateral certificates enough?

Formally, yes. But we also recommend specifying the acceptance procedure, deadlines for objections, and the consequences of the counterparty's silence. Without this, the contract will not protect you in a dispute over the scope or quality of services.

Can an invoice replace a certificate?

It can, if it contains all the mandatory details of a source document and the date or period of service provision.

Will a court recognize a certificate without the client's signature?

Yes. The Supreme Court recognized unilateral certificates even before the changes, if the client did not prove the validity of their refusal to sign (case No. 910/5352/21). As of April 1, 2026, the contractor's position has become even stronger.

From what date do the new rules take effect?

From April 1, 2026. Law No. 4791-IX was adopted on February 24, signed on March 16, and published on March 17, 2026.

Conclusion

The model without a second signature is suitable for companies with recurring transactions, an established electronic document workflow, and well-drafted contracts. For others, it will bring more complex contracts, new wording in documents, and tax questions without established answers. The system has become more flexible. It has not become simpler.