The first missed rent is the cheap one: a Flemish timeline
By UnitDeskPublished
A registered formal notice on day 15 costs a Flemish landlord 9.85 euro; waiting until the third missed month costs three months of rent plus a court file. The postage is bpost’s 2026 tariff for a domestic registered letter, and three months is the arrears level the justice of the peace weighs heavily in practice. Everything in between is a choice about timing, and the timing has a price.
Which letter the law asks for
The Flemish Residential Lease Decree says a lease is dissolved when the tenant fails to meet their obligations, and that a tenant at fault keeps paying rent for the time it takes to re-let (art. 40). It does not say how you get there. That sits in general contract law: Book 5 of the Civil Code lets a creditor dissolve a contract when the other side’s breach is serious enough (art. 5.90), and every one of those remedies must be preceded by a formal notice (ingebrekestelling, art. 5.83). The same notice starts default interest at the legal rate, 4.50% a year in 2026, without you having to prove any damage (art. 5.240). There is no statutory threshold in months. “Serious enough” is the only test, and the consumer organisation Test-Aankoop puts the practical bar at two or three months of arrears.
That is why the registered letter matters more than any other step. It is required before dissolution, it dates the debt, and it fixes the amount you can later prove. bpost delivers it the next working day and, since 2026, a registered item may contain documents only, so the letter is the whole file: the lease, the unpaid months, the total and a deadline.
The timeline in days and euros
Rent of 900 euro a month, due on the first, as an example.
| Day | Step | What it costs you |
|---|---|---|
| 0 | Rent due, nothing arrives | Nothing yet |
| 5 | Informal reminder by email or message | 0 euro |
| 15 | Registered formal notice naming the months, the total and a deadline | 9.85 euro postage, 11.49 with a receipt slip; interest starts at 4.50% a year, 3.38 euro a month on 900 euro |
| 30 | Second month due; propose a written repayment plan | 0 euro; Flanders publishes a model agreement in which the OCMW guides the tenant |
| 60 to 90 | Two or three months open: ask the justice of the peace for a conciliation | Free; a simple request at the court registry |
| 90 and later | Claim by petition: payment, dissolution and eviction | 50 euro court fee; the parties are summoned within 15 days of enrolment; the registry sends a copy of the petition to the tenant’s OCMW; the judge always tries to conciliate first |
| Judgment plus one month | Earliest eviction, one month after the judgment is served | Bailiff costs |
| 5 years | Arrears older than this lapse, month by month | The months you never claimed |
The interest line is small on purpose. On 900 euro the legal rate earns you 3.38 euro a month, so waiting is not compensated by interest. What waiting produces is a larger principal: 1,800 euro after two months, 2,700 after three, against a deposit that the decree caps at three months’ rent and that you cannot touch unilaterally. The deposit account is only released with a written agreement drawn up at the end of the lease at the earliest, or a copy of a court decision (art. 37), and your own claim on it lapses one year after the lease ends.
Write the notice from your records, not from memory
The notice has to name the months and the amount. A landlord who tracks rent in a spreadsheet writes it from a column that was last reconciled when the bank statement was downloaded, and a tenant who paid 600 of the 900 in a month will contest a letter that says the month is unpaid. The judge reads the letter next to the bank statements; when the two disagree, the letter loses.
So the first missed rent is the cheap one for two reasons. The letter is 9.85 euro on day 15 and the same 9.85 euro on day 90, but on day 15 it covers one month and the tenant still has the money. And a notice written from a reconciled ledger survives the hearing; one written from a feeling about who paid what does not.
What UnitDesk records here
Each lease in UnitDesk shows which months are paid, partially paid or open, with the amount per month, because imported bank transactions are matched to the lease. For the notice you copy that list. At the end of the lease you record a deduction from the deposit for unpaid rent, with the reason, so the settlement matches what was still outstanding. UnitDesk does not collect rent; it follows what arrives on your account. The law behind each step is in the guide Tenant not paying rent in Flanders: what to do.
Sources
- bpost, practical guide for private mail from 1 January 2026 (registered letter, Belgium, 0 to 50 g: 9.85 euro) and tariffs for private customers (receipt slip: 1.64 euro).
- Civil Code, Book 5, law of 28 April 2022: art. 5.83 (remedies and the prior formal notice), art. 5.90 (dissolution for a sufficiently serious breach), art. 5.240 (default interest at the legal rate from the formal notice).
- Legal interest rate 2026: 4.50% for civil matters, Lawbase overview of the legal interest rate.
- Flemish Residential Lease Decree of 9 November 2018, consolidated text on Codex Vlaanderen: art. 37 (deposit of at most three months, release by written agreement or court decision), art. 40 (dissolution when a party fails to meet their obligations), art. 43 (the justice of the peace hears every lease dispute regardless of amount), art. 45 (claim by petition, parties summoned within 15 days), art. 46 (the registry notifies the OCMW of every eviction claim), art. 47 (the judge always tries to conciliate), art. 48 (eviction one month after service of the judgment).
- Old Civil Code, art. 2277: rent lapses after five years.
- Belgian courts, the justice of the peace: conciliation is free, court fee 50 euro.
- Flemish Government, model agreement on the repayment of rent arrears with OCMW guidance, annex to the decision of 3 May 2019.
- Test-Aankoop, tenant not paying in Flanders: two or three months of arrears in practice.