A statement of open items (IOS, from the Serbian izvod otvorenih stavki) is the document a company uses to reconcile balances with its customers and suppliers before preparing its annual financial statements. The obligation comes from the Serbian Law on Accounting, and in practice statements are sent in the second half of the year, most often in October or November.

The purpose is simple: the amounts in your books should match the amounts in your business partners’ books. If they don’t, the error is found and corrected before the year-end closing, while it is still easy to fix.

What the law says and who must reconcile

Article 22 of the Law on Accounting (Official Gazette of RS, Nos. 73/2019 and 44/2021) requires legal entities and entrepreneurs to reconcile mutual receivables and payables before preparing their financial statements, and to support the reconciliation with an appropriate document. The creditor must send the debtor a list of unpaid obligations.

The law does not prescribe a form. The statement of open items developed in practice and is now the standard document used to prove that balances have been reconciled.

The obligation applies to:

• companies and other legal entities,
• entrepreneurs (sole traders) who keep business books.

Entrepreneurs taxed on a flat-rate basis do not keep business books, so they have no obligation to reconcile balances. A flat-rate entrepreneur does not send IOS statements to customers.

Who sends it, and as of which date

The IOS is sent by the creditor to the debtor, that is, by the seller to the buyer. In practice most companies send statements only to their customers and reconcile supplier balances through the statements they receive from suppliers. This avoids reconciling the same balance twice. If one of your larger suppliers does not send you a statement, it is good practice to send one to them yourself.

A statement is also sent to partners with no open items on the reconciliation date, if there was trading with them during the year. A confirmed zero balance is also proof of reconciliation.

The law does not set a date. The date as of which balances are stated is set by the company’s internal rules, usually its accounting policy. In practice it is the last day of a month in the second half of the year, chosen to suit the company’s workflow. What matters is that the month has been fully posted before the statements are prepared.

What an IOS contains

Information	Why it is needed
Sender and recipient details (name, tax ID, address)	Identifies the parties reconciling balances
Balance date	Both sides compare their books as of the same day
List of open invoices: number, date, amount, paid, outstanding	The recipient compares item by item, not just the total
Total balance and who owes whom	A quick overview of the position
Response section: agree / disagree, with the amount in the recipient’s books	The document returned to the sender
Signature or other identifying mark of the authorised person, and a response deadline	Makes the document valid

How it is sent today: email is enough, no stamp needed

Statements used to be sent by post, in two copies, stamped and signed. That is no longer required.

The Law on Accounting recognises accounting documents in electronic form. Such a document must carry the signature or another identifying mark of the responsible or authorised person, or an electronic signature. An IOS sent by email as a PDF, showing the name of the person who issued it, meets this requirement.

The law does not require a company stamp. A note saying “valid without stamp and signature” is not enough on its own: the document must still show the name or another identifying mark of the authorised person.

If you need proof that the statement was delivered, keep the sent email, and for partners who do not respond, also send it by registered post.

When the balances don’t match

A difference almost always has an ordinary cause: an invoice one side has not yet posted, a payment posted to the wrong partner, a credit note that has not reached the customer, or an advance recorded as payment of an invoice. A recipient who disagrees should state the balance from their own books and, if known, the reason for the difference.

Both sides then check their ledgers and correct errors before the year-end closing. If the difference cannot be resolved, legal entities that prepare Notes to the financial statements must disclose the unreconciled receivables and payables as a total amount.

When the other party does not respond

The sender has met its obligation once the statement has been delivered. The obligation to reconcile also applies to the recipient, so a partner who does not respond or refuses to accept the statement is the one in breach of the law, not you.

A note on the statement saying the balance will be deemed reconciled if no reply is received by a certain date has no clear basis in the law. It is safer to treat such a balance as unreconciled.

An IOS is not a payment reminder

Customers sometimes read an IOS as a demand for payment and get in touch, confused because their payment is not yet due. The statement only shows the balance in the books on a given date; it is best passed straight to the accountant.

IOS, acknowledgement of debt and the limitation period

An IOS signed by the debtor’s authorised person may be treated as an acknowledgement of debt, and acknowledging a debt interrupts the limitation period for the claim. This gives the statement value in debt collection, not only in bookkeeping.

The Serbian Commercial Appellate Court has held that an accountant’s signature on an IOS is not an acknowledgement of debt and does not waive the limitation period, unless the accountant is authorised by the company’s legal representative. When the statement matters to you as evidence of a debt, ask for the signature of the director or a person authorised by them.

Penalties

Articles 57 and 58 of the Law on Accounting set penalties for a creditor that does not send the debtor its balance of unpaid invoices, and for a legal entity that does not disclose unreconciled receivables and payables in the Notes:

Who	Type of offence	Fine (applicable in 2026)
Legal entity	commercial offence	RSD 100,000 – 3,000,000
Responsible person in the legal entity	commercial offence	RSD 20,000 – 150,000
Entrepreneur	misdemeanour	RSD 100,000 – 500,000

Frequently asked questions

Does an IOS need a company stamp?

No. A signature or another identifying mark of the authorised person is enough, on paper or in an electronic document.

Can I send an IOS by email?

Yes. An IOS in electronic form is a valid document if it shows the name or another identifying mark of the authorised person.

What if the balance with a partner cannot be reconciled?

Both sides check their ledgers and correct errors. Any remaining difference is disclosed in the Notes to the financial statements.

What if a partner refuses to accept the IOS?

You have met your obligation by delivering it. Keep proof that it was sent and treat the balance with that partner as unreconciled.

Does a flat-rate entrepreneur send IOS statements?

No. A flat-rate taxed entrepreneur does not keep business books and therefore has no obligation to reconcile balances.

How we handle this for our clients

For clients whose books we keep, we prepare the statements ourselves in our accounting software, based on up-to-date customer and supplier ledgers. We send the prepared statements to the client, who forwards them to their customers.

As an additional service, we also offer automatic sending: statements go directly from the accounting software to the customer email addresses the client provides. The client does not have to send them one by one, and we can see straight away what has been sent.

We check the statements the client receives from suppliers and reconcile them in the books before the year-end closing.

Important for our clients: do not confirm or return an IOS you receive from a supplier or customer before checking with us. A signed statement may amount to an acknowledgement of debt, so we first check the balance in the books, and only then do you confirm or dispute it.

See our services or get in touch if you would like us to keep your books.