The C4 form, in full the C4 unemployment certificate (werkloosheidsbewijs), is the document you as an employer give every employee whose employment contract ends, on your own initiative and at the latest on the last working day. That also applies when the employee resigns, when a fixed-term contract expires or when he retires. You choose how: a paper C4, or the electronic social risk declaration (ASR scenario 1, aangifte sociaal risico) plus the paper C4-ASR form for the employee.
The C4 is one of the documents that come with a departure. The full list, with the deadline for each document, is in social documents at the end of employment. This guide covers only the C4: when you draw it up, how, what you fill in and what it costs when it goes wrong. What you arrange for the dismissal itself is in dismissal in Belgium.
When do you issue the C4 form?
The rule is in article 137 of the royal decree of 25 November 1991 on unemployment regulations. The National Employment Office (RVA) sums it up like this: at the end of an employment contract, whoever takes the initiative, you must give the employee an unemployment certificate immediately and on your own initiative. Whether the employee plans to claim benefits makes no difference.
| End of the contract | C4 required? |
|---|---|
| Dismissal by the employer, also for serious cause | Yes |
| Resignation or voluntary departure by the employee | Yes |
| End by mutual agreement | Yes |
| Force majeure, including medical force majeure | Yes |
| End of a fixed-term contract or a contract for a specific job | Yes |
| Bankruptcy | Yes |
| End of a student employment contract | Yes |
| End of employment with a view to retirement | Yes |
| Successive contracts with the same working-time fraction, interrupted only by a weekend, a public holiday or a compensatory rest day | One C4 when the employee finally leaves |
| Contract still running, the employee asks for proof of work | Yes, at his request |
For successive contracts with a different working-time fraction, the rule changes. If the fraction goes up, you draw up a C4 for each period of employment in principle, except for periods the NSSO has already accepted in your quarterly declarations. If it goes down, the employee may be entitled to an income guarantee allowance and you must give him a C4 for the previous contract at his request.
A part-time employee who temporarily works full-time through an addendum or an extra part-time contract can go back to his old hours without ASR scenario 1, provided the full-time work did not exceed 3 full calendar months. If the employee asks for it, you file the declaration anyway.
The C4 form deadline: the last working day
The legal text is short: the employer hands over the unemployment certificate on his own initiative, at the latest on the last working day. For the electronic route, the NSSO says the same: the declaration is made immediately and on your own initiative, at the latest on the last working day.
In practice this means:
- If the employee works his notice, the last day of the notice is the deadline. You know that date weeks ahead: put it in the diary straight away.
- If you terminate with compensation in lieu of notice, the last working day is the day of the termination. The C4 must be ready that day, not after the next payroll run.
- For a fixed-term contract, the last day of the contract is the deadline, even if you are still unsure about an extension.
C4 form in Belgium: electronic or on paper
| Route | What you do | What the employee receives |
|---|---|---|
| Paper C4 | You fill in the form, sign it and hand it over | The signed C4 form |
| ASR scenario 1 through the web application | You file the declaration on the social security portal and validate it | A copy of the declaration and the C4-ASR form, which you complete |
| ASR scenario 1 by batch | Your software or social secretariat sends structured messages | The same copy and the C4-ASR form |
For the web application you must be registered as an employer on the social security portal. The RVA recommends it for a limited number of declarations, and batch for large volumes.
The paper part stays. Even if you file electronically, you fill in yourself on the C4-ASR form how the employment ended and which compensation you paid, together with the start date of employment. The form is available as soon as you validate the electronic declaration, with the ticket number already filled in. The copy is drawn up in the language of the region where the employee works: for a site in Ghent, that is Dutch. You may add a translation.
If you use the paper C4, use the right version. For an exit after 31 October 2023, the RVA only accepts the version of 6 July 2023. An old form from a folder or an old download is not accepted.
Does anything change in 2026 or 2027? The electronic declaration is not a duty: article 138bis of the unemployment decree excludes the unemployment certificate from the obligation to transmit data electronically. On 20 October 2026 we found no announced change to the paper form or to that choice on the RVA and NSSO websites. The RVA does write that an electronic declaration containing all the data is under development, without a date.
How you state the reason for the end on the C4
This is the part where things most often go wrong, and the part that matters most to the employee. The RVA uses it, among other things, to check whether the unemployment is involuntary. That is one of the essential conditions for being admitted to benefits. The table comes from the RVA employer information sheet E14 and applies to the paper C4 and to the C4-ASR form.
| How the employment ended | Date you fill in | Fill in the exact cause of unemployment? |
|---|---|---|
| Notice given by the employer | Date the registered letter was sent, or date of service by bailiff | Yes |
| Termination by the employer | End date of the employment contract | Yes |
| By the employee | Date the employee voluntarily left the job | No |
| By mutual agreement | Date of the agreement on the end | Yes |
| Force majeure due to the employee's permanent incapacity for work | None | No |
| Force majeure for another reason | Date on which force majeure was invoked | Yes |
| Fixed-term contract | End date of the contract | No |
| Contract for a specific job | Date the job was completed | No, the employee attaches the contract to his claim |
Three situations need extra care:
- Notice that ends through force majeure. If the contract ends during the notice for another reason, you tick two boxes, for example notice by the employer and force majeure.
- Medical force majeure. You tick force majeure due to permanent incapacity for work, with no date and no cause. How to follow that procedure correctly is in medical force majeure.
- A reason not on the list, such as judicial dissolution or a resolutory condition. You tick nothing and explain it under Remarks.
Write on the C4 what really happened, in the same words as in the dismissal letter or the agreement. An agreement recorded on the C4 as a dismissal, or the other way round, leads to questions from the RVA and to a dispute with the employee. How to draw up an agreement and what it means for benefits is in termination by mutual agreement.
C4 form when the employee resigns
If the employee resigns, the C4 remains mandatory. You tick that the contract ended by the employee, fill in the date he voluntarily left the job and leave the cause of unemployment empty. Whether the employee then receives benefits is for the RVA to decide, not you.
Sometimes a departing employee asks you to write "mutual agreement" or "dismissal by the employer" on the C4, to improve his chances of benefits. Do not do it. Incorrect or incomplete statements about the dismissal are a level 2 offence under the Social Criminal Code, just like a late C4.
Compensation in lieu of notice and other payments on the C4
In the part on compensation, the RVA checks whether the notice rules were followed and whether the employee received a payment that cannot be combined with unemployment benefits.
- The employee works his notice. You state the period of the original notice, whether the notice was suspended and extended, whether the employee was fully or partly released from work and from when, and whether he followed a transition track with another employer during the notice. Leave to look for a job does not count as release from work.
- You pay compensation in lieu of notice. The end date of employment on the C4 is the day of the termination. For the compensation you fill in the period covered by the compensation in lieu of notice.
- Outplacement. If the employee is entitled to notice or compensation of at least 30 weeks, he is entitled to outplacement and you indicate that the compensation is reduced. The reduction is in principle 4 weeks. If you did not reduce it, you explain why under Remarks.
- Illness during the notice. If you terminate the contract during an incapacity for work that started during the notice, you may deduct the guaranteed pay since the start of that incapacity from the period the compensation covers. You state that as well.
- Other payments, such as a goodwill indemnity for a sales representative, compensation for a non-compete clause or a payment on termination by agreement, go in a separate item.
- Contract from before 2014. You then split the notice or compensation into part A and part B, as information sheet E14 explains. That no longer applies to a resignation by the employee from 28 October 2023.
Worked example. A white-collar employee has been employed since 1 June 2021. You end the contract on Friday 13 November 2026 with compensation in lieu of notice. With 5 years and 5 months of seniority, his notice period is 18 weeks.
| On the C4 | What you fill in |
|---|---|
| Start date of employment | 1 June 2021 |
| End date of employment | 13 November 2026, the day of the termination |
| How the employment ended | Termination by the employer, date 13 November 2026, with the exact cause of unemployment |
| Period covered by the compensation | 18 weeks: from 14 November 2026 up to and including 19 March 2027 |
| Outplacement | Not ticked: the compensation stays below 30 weeks |
| Deadline for the C4 or the ASR with the C4-ASR | 13 November 2026 |
According to the RVA, compensation in lieu of notice cannot be combined with unemployment benefit. Up to and including 19 March 2027, the employee therefore receives no benefit. An error in that period shifts his rights, and he notices it at once.
Timeline for an extended temporary contract. An employee has a fixed-term contract until Friday 18 December 2026. On Monday 21 December 2026 a new contract starts with the same hours. Only a weekend lies in between, so you do not issue a C4 for the first contract: one C4 when he finally leaves is enough. If the employee still asks for a C4 as proof of work, you give it to him.
Late or wrong C4 form: what the employer risks
Article 226 of the Social Criminal Code punishes with a level 2 sanction the employer who refuses or fails to draw up, issue or complete the documents of the unemployment decree within the deadlines. The same level applies to incorrect or incomplete statements about the dismissal. For offences from 1 February 2026, the administrative fine is € 250 to € 2,500. Since 1 July 2024, that fine is multiplied by the number of employees concerned.
If you refuse to issue a C4, the RVA social inspector can draw up the form himself and write an official report for failing to draw up prescribed documents.
For the employee, the consequences are more direct. Without a C4 his benefit file is incomplete: he files his claim with a different form and must still provide the C4 as soon as possible. So he comes back to you.
Correcting an error. For the electronic declaration, the NSSO writes that incorrect entries can lead to a request for an amending declaration. The RVA information sheet does not describe how to correct a paper C4. Talk to your social secretariat before you draw up a second form, so that no two conflicting versions are in circulation.
Mistakes employers make with the C4 form
- Drawing up the C4 only after the last payroll run. The deadline is the last working day.
- No C4 after a resignation, a retirement or a student contract. It is mandatory then too.
- Using an old paper form. For every exit after 31 October 2023, only the version of 6 July 2023 is valid.
- Forgetting the C4-ASR form after the electronic declaration. The employee needs both.
- Confusing the date of the registered letter with the end date. For notice by the employer, the RVA asks for the date the letter was sent.
- Starting the compensation period on the day of the termination. It starts the day after.
- Writing a different reason than in the dismissal letter. The RVA uses the reason to check whether the unemployment is involuntary.
C4 certificate in Belgium: how the employee obtains it
According to the RVA, the employer must give the C4 on his own initiative, at the latest on the last working day; the employee does not have to ask for it. With the C4, the employee files his benefit claim with the payment institution of his choice. If he does not get the C4 in time, he files the claim with that institution's C109 form and must do everything to obtain the C4 quickly. While the contract is still running, he can ask for a C4 as proof of work, and you must give it.
The C4 rarely comes alone. For a white-collar employee you also issue a holiday certificate, and every employee later receives a copy of his individual account.
What Business Centrum does
When an employee leaves, Business Centrum draws up the social documents as part of your personnel administration and payroll, together with Acerta, including the C4 through the electronic declaration and the C4-ASR form. You pass the end of the contract to your fixed contact person, with the dismissal letter or the agreement, and you receive the documents to hand to the employee. Want to know how that works for your business? Ask us.