Neither sending nor receipt: the 1st of the following month
The notice period does not start on the day of sending or the day of receipt. It starts on the 1st day of the month following receipt of the registered letter. Receipt is legally presumed on the 3rd business day after sending. This gives a clear, uniform starting point.
The calculation involves three dates:
- Sending date: the day you post the registered letter
- Presumed receipt date: 3 business days later (excluding Saturdays, Sundays, and public holidays)
- Notice start date: the 1st of the month following the presumed receipt
This means there is always a “buffer” period between sending and the start of the notice. The tenant continues to owe rent during this buffer period and throughout the full notice.
Practical examples
| Sent on | Presumed receipt | Notice starts | 3-month notice ends |
|---|---|---|---|
| Monday 10 March | Thursday 13 March | 1 April | 30 June |
| Thursday 27 March | Tuesday 1 April | 1 May | 31 July |
| Friday 28 February | Wednesday 3 March | 1 April | 30 June |
| Wednesday 26 December | Monday 30 December | 1 January | 31 March |
Business days exclude Saturdays, Sundays, and public holidays. If the sending date falls on a Friday, the 3-day count starts on Saturday but only counts Monday, Tuesday, and Wednesday as business days. In practice, send early in the week and early in the month for predictable results.
What if the letter is not collected?
If the recipient does not collect the registered letter from the post office:
- The presumption of receipt on the 3rd business day still applies
- The notice is valid regardless of whether the letter is actually collected
- The recipient cannot avoid the notice by refusing to collect the letter
- The proof of sending (postal receipt) is sufficient evidence
This is an irrebuttable presumption (presumption juris et de jure) — the recipient cannot argue that they never received the letter to invalidate the notice.
However, if the letter is sent to the wrong address, the notice is invalid. Always send the registered letter to the address specified in the lease for correspondence.
Regional specifics
Brussels-Capital Region
The Ordinance of 27 July 2017 does not modify the receipt presumption or notice start rules. The federal rules apply.
Wallonia
The Decree of 15 March 2018 applies the same framework.
Flanders
The Flemish Housing Rental Decree of 9 November 2018 applies the same receipt presumption rules.
Judicial Code, article 53bis (presumption of receipt on the 3rd business day). Law of 20 February 1991 (notice period rules).