Ombudsfin complaint: the procedure step by step

You write first to the complaints department of the bank or card issuer, then lodge the case with Ombudsfin, the financial mediation service, through its online form, within a year of that first complaint. Mediation costs the complainant nothing and takes 90 calendar days in principle. The final opinion does not bind the bank.

A seller who never delivered is a matter for the chargeback. Here the bank is the target: a disputed fraud, fees charged by mistake, a card blocked without reason.

The bank has five days to acknowledge receipt

Febelfin's code of conduct on complaint handling, adopted on 27 March 2009, requires every institution to have a department or a person in charge of complaints and to send an acknowledgement within 5 working days. It asks institutions to make an effort to reply within a month. It is a trade-federation recommendation seventeen years old, with no force of law, and I found no sanction attached to ignoring it.

Banks set their own, more precise deadlines. The deadlines I re-read on 23 October 2026, bank by bank, with Ombudsfin's alongside:

My count for a complaint posted on Monday 26 October 2026, with 11 November a public holiday: acknowledgement by Monday 2 November at the latest, an answer on a disputed payment by Tuesday 17 November, an answer on any other subject by Wednesday 25 November at KBC Brussels. The date of that first sending also starts the one-year clock: 26 October 2027 is the last day to write to Ombudsfin.

Belfius gives no number of days on the page I read, only "as soon as possible", and the page is devoted to its public and social segment. I therefore left it out of the table. The waiting times for every stage of a card are gathered in our guide to credit card timeframes.

What goes in the complaint letter?

A dated piece of writing, and nothing else counts.

An adviser who promises at the counter to "pass it up the line" gives you no date, yet it is the date of the first complaint that starts the year. I would never rely on a verbal exchange. The way forward takes five steps.

1. Note the facts: date, amount, last four digits of the card, the merchant or channel involved.
2. Write what you are asking for: refund of a precise sum, cancellation of fees, unblocking of the card.
3. Attach the useful documents (list below).
4. Send it through a channel that leaves a trace: the bank's online form, its app if it accepts complaints (KBC Brussels does), or a registered letter. Keep the acknowledgement.
5. Write the sending date in your diary, next to the deadline for the answer.

A model to adapt, without empty phrases:

Subject: complaint, transaction of [date] for [amount] EUR, card ending [four digits]

Dear Sir or Madam,

On [date], a transaction of [amount] EUR was debited from my card in favour of [payee]. [I did not authorise it. / This sum is charged to me wrongly for the following reason: ...]

I ask you to [refund / cancel / correct] this transaction and to reply in writing. The documents listed below are attached.

Failing a satisfactory reply, I will refer the matter to Ombudsfin.

[Name, address, customer number, signature]

Documents to attach:

• the card statement with the transaction marked;
• screenshots of the payment, of the message received or of the app;
• earlier written exchanges with the adviser or the merchant;
• the card's general terms, when the complaint concerns fees;
• proof that this letter was sent.

For a fraud, the emergency steps (blocking, reporting) come before the letter: they are in our guide to credit card fraud. A sum you are waiting for from a merchant is followed in the one on repayment.

Can Ombudsfin handle my case?

Not always, and the grounds for inadmissibility are more numerous than people expect.

The bank must also be a member of Ombudsfin and you must act for yourself. Since January 2026, micro-enterprises and small companies can also go to the service, according to Test-Achats (article of 16 February 2026, in French). Wikifin adds that Ombudsfin does not automatically take the complainant's side: it mediates. The vocabulary of all these players is set out in our glossary of law and players.

The sources disagree on the preliminary step. Ombudsfin's FAQ says you need not prove the bank handled the complaint, while advising you to write to it first. Test-Achats writes that prior contact is no longer strictly required. Another Ombudsfin page, read the same day, makes the complaint to the bank a condition, with a 30-day wait before going to the mediator.

I follow the most cautious reading: letter to the bank first, filing with Ombudsfin as soon as the answer arrives or the announced deadline has passed. While waiting, I already prepare the mediator's file, so that the bank's month does not delay everything else by as much. The pillar on cardholder rights places this step in the full ladder, from the bank to the judge.

The online form takes sixty lines, or an attached file

The complaint is filed from the green "Introduire une plainte" button on the Ombudsfin site (French), which leads to the portal my-ombudsfin.compman.be. The site asks you to always use this form rather than email. The text fits in a box of 60 lines at most, or in an attached file. Postal mail remains possible at North Gate II, boulevard du Roi Albert II 8, box 2, 1000 Brussels. In every case, the complaint must be in writing.

Sixty lines rarely suffice for a fraud file. I would put two or three summary lines in the box and the full chronological account in the attached file, with the letter to the bank and its reply. Ombudsfin warns that the documents you send may be passed on to the institution concerned, so nothing private or irrelevant.

The stages described on the procedure page run like this: acknowledgement, admissibility check, investigation by a case handler (90 calendar days in principle, renewable for the same period), then a written opinion sent to each party. A file lodged on 2 December 2026 would therefore reach its in-principle deadline on 2 March 2027, and 31 May 2027 after renewal.

I keep one worry: the site admits a backlog in handling cases. The phone, on +32 2 545 77 70, temporarily answers only on Wednesdays. The 71.2-day average dates from 2025, and I do not know what the 90 days of principle are worth today.

Does Ombudsfin's opinion oblige the bank?

No, except for the basic banking service. The FAQ says institutions have committed to taking an active part in mediation, but Test-Achats notes that some refuse to take part and that only a court action then imposes a decision.

I consider this the most uncomfortable point of the system. A complainant may wait three months, even six, for an opinion that the bank is entitled to ignore.

The success rate is nevertheless high: according to Ombudsfin's 2025 annual report, 82.5% of complaints judged well founded ended in a successful mediation (figure noted in our glossary on 17 September 2026). It should be read with its limit: it measures only the complaints judged well founded, not all the cases filed.

What if the opinion settles nothing?

The opinion is final and ends the mediation. A revision is possible only for a material error, within three months of receiving it.

The court remains open to both parties, and the opinion can serve there as evidence. If Ombudsfin was not competent, Wikifin points to the contact point of the federal economy ministry (SPF Économie), which analyses the report but does not intervene in your individual case. Test-Achats' legal service can help draft the complaint or choose the next step. Legal expenses insurance sometimes covers the cost of proceedings, hence the value of reading your policy before paying a lawyer.

When it is the relationship with the issuer that has broken down, our guide to cancelling a credit card describes the exit, and the article on credit register listing says what stays on the register after a payment dispute.

On 23 October 2026, Ombudsfin answers the phone only on Wednesdays, and its site asks you to use the online form.