A lease amendment is a modification act that allows adapting the terms of a rental contract during its execution. It is a written agreement between landlord and tenant that supplements or modifies the original lease.
Key points:
- The amendment does not replace the lease: it supplements it
- It must be signed by all parties to the lease
- It takes effect on the date agreed by the parties
- It must be registered like the lease itself
The amendment is the legally correct method to modify a lease. Any oral or non-formalised modification is legally fragile and unenforceable against third parties.
The most common situations requiring an amendment:
Financial modifications:
- Change in rent amount (outside indexation)
- Change in charges amount
- Change of bank account for payment
Party modifications:
- Addition or removal of a co-tenant
- Change of landlord (property sale)
- Death of a party
Property modifications:
- Works modifying the surface area (addition of garage, cellar…)
- Change of use for part of the property
- Addition of furniture or equipment to the lease
Duration modifications:
- Extension of a short-term lease
- Reduction of the agreed duration
To be legally valid, the amendment must contain:
| Item | Detail |
|---|---|
| Lease reference | Date of lease, property address, parties |
| Subject of modification | Modified clause(s) clearly identified |
| New text | Exact wording of the new clause |
| Effective date | Day from which the modification applies |
| Maintenance clause | ”All other clauses remain unchanged” |
| Signatures | All parties to the lease + date |
| Number of copies | One per party + one for registration |
Tip: reproduce both the old clause AND the new one in the amendment to avoid any ambiguity.
Registration is mandatory for amendments modifying:
- The rent amount
- The lease duration
- The parties to the contract
- The property’s use
Procedure:
- Submit the amendment to the Legal Security office (online or at the counter)
- Deadline: 2 months after signing
- Cost: free for primary residence leases
- Commercial leases: registration fee of 0.2% if rent increases
Generate your amendment directly on LeaseBelgium: the document is pre-filled with your lease information and ready for electronic signature.