The guarantor of a lease: what they sign, what they risk

"Someone will just have to sign for you." The sentence sounds harmless; the undertaking is not. A guarantor is not doing a favour: they are taking on a debt, someone else's, which they will pay if that person does not. Before you ask a parent or a friend to sign, you need to know exactly what you are asking.

Compatri does not let housing and plays no part in your lease: this guide helps you understand your rights and find the right people to talk to.

What a surety is

The guarantor (the surety, in legal language) undertakes towards the landlord to perform the tenant's obligations if the tenant does not. It is not a contract between guarantor and tenant: it is a contract between the guarantor and the owner. The tenant is not even necessarily a party to the deed.

The rules changed on 1 January 2026. Book 9 of the new Civil Code ("Securities", Act of 5 June 2025) replaces the old Civil Code articles on suretyship, including the 2007 regime for the "gratuitous surety". It applies to sureties given since that date; an undertaking signed before 2026 remains, in principle, under the old text.

For a guarantor acting privately, such as a parent backing their child's student room, the new text provides in every case that:

• the undertaking must be proportionate to their assets and income: if it was manifestly disproportionate when signed, it is reduced to what the guarantor could pay (the guarantor must prove the disproportion);
• ancillary sums (interest, costs) may not exceed 50 % of the principal claimed;
• for future debts, it only covers those arising from an existing contract designated in the deed, here the lease;
• their heirs are only liable up to their share of the estate.

Where the landlord acts in a professional capacity, further protections apply: a written deed separate from the lease, on pain of nullity, a maximum amount that must be stated, and information for the guarantor before signing, then every year, and without delay if payments are missed. With a landlord who is not acting professionally, those rules do not apply automatically: all the more reason to insist yourself on a clear written deed with a cap. If you are asked for a sum out of all proportion to your means, have the deed read by a lawyer.

Simple or joint-and-several surety: the expensive difference

This is the point almost nobody checks, and the one that really changes the guarantor's life.

By default, a surety is subsidiary. The guarantor only has to pay once the tenant has been given formal notice of default, and a landlord who serves that notice must inform the guarantor at the same time. Above all, the landlord must first make an appropriate attempt to obtain payment from the tenant: this is the benefit of discussion. They are only excused from it where that is manifestly impossible or excessively difficult, for instance in bankruptcy or collective debt settlement.

A joint-and-several surety loses the benefit of discussion. The tenant must still have been served notice of default, but the landlord can then turn straight to the guarantor, without first trying to recover from the tenant. It is a common clause in model leases, because it is the one a landlord cares about. A joint guarantor is still a guarantor, not a co-tenant; but in practice they are in the front line.

Several guarantors? Under the new Code, each surety is jointly and severally liable with the others, within the limit of their own undertaking; they then share the burden between themselves in proportion to their undertakings. The old "benefit of division", which limited each guarantor to their share, is no longer the default rule.

A guarantor who pays then has a claim against the tenant. Solid in theory, hard in practice: if the tenant did not pay, it is rarely because they had the money.

Check the deed for: the words "joint and several", the maximum amount and the duration.

How far the undertaking goes

Three questions to put to the owner before signing. If the answers are not in the deed, have them added.

What amount? Insist on a quantified maximum amount, for example "rent and charges, up to a maximum of €X". With a professional landlord it is a legal requirement; with a private one it is your best protection. An undertaking "for all the tenant's obligations", with no cap, is an undertaking of unknown size.

For how long? A nine-year main-residence lease, with its rent indexation, can add up to considerable sums. A guarantor may legitimately limit the commitment: to three years, to the initial term, to one academic year for a student lease. It is negotiable, and far easier before signing than after. If the deed sets no duration, the new Code lets the surety be ended on reasonable notice (forty-five days, unless a shorter period was agreed); the guarantor remains liable for what was owed before. For a gratuitous undertaking signed before 2026 covering an obligation of indefinite duration, the old regime capped the duration at five years.

And if the lease carries on? The Regions handle this differently. In Flanders, the decree provides that the guarantor's obligations remain in force after the lease is extended and after its conversion into a nine-year lease. In Wallonia, where a fixed-term lease is renewed because the tenant stays on without objection from the landlord, the surety's undertaking does not, unless otherwise agreed, extend to the renewed lease.

What exactly? Rent alone? Charges? Damage? Interest and legal costs? Every item added widens the exposure. A clean deed lists them.

Finally, the guarantor is not the tenant: they have no right over the property, no right of access, no say in how their child occupies it. They have only the duty to pay. Better to absorb that imbalance before signing.

Guarantor and rental deposit: what the Regions say

Brussels. For leases entered into or renewed since 1 November 2024, a personal guarantee is one of the five permitted forms of rental deposit, and Brussels Housing states that the deposit, whatever its form, may not exceed two months' rent. It may only be added on top of the other forms (blocked account, bank guarantee…) for a student lease.

Flanders. For leases since 2019, a personal guarantee is only possible with the landlord's agreement, and as an alternative: it can no longer be combined with a deposit in a blocked account.

Wallonia. The decree regulates the rental deposit (blocked account, bank guarantee or guarantee through the welfare centre, at most two months' rent) and contains the renewal rule mentioned above. If in doubt about what a landlord may demand on top, have the lease checked by a housing service or tenants' association.

What a guarantor must provide, and what may not be demanded

A landlord accepting a guarantor wants to be satisfied they are solvent. They may therefore reasonably ask for:

• an identity document;
• proof of income: the last three payslips, or a tax assessment notice for a self-employed person or pensioner;
• possibly proof of ownership or an outline of their assets, where the commitment is large.

What they may not demand, from the guarantor no more than from the tenant: a criminal record extract, health data, information on ethnic origin or religion, or full unredacted bank statements. The same limits apply as for the tenant (see our guide to building a tenant file). And a rejected guarantor's documents must likewise be destroyed.

No guarantor? There are ways out

Do not assume a file without a guarantor is a dead file. Several levers exist, to be combined.

A well-constituted deposit. A blocked account funded in one payment is reassuring. The cap is two months' rent in Brussels (leases since 1 November 2024) and Wallonia (since 1 June 2023), and three months in Flanders; everything is in our guide to the rental deposit.

The bank guarantee. In Brussels and Wallonia, the bank into which your income is paid can guarantee the amount to the landlord, which you then build up in instalments over three years at most; it may not refuse you on the ground of creditworthiness.

The welfare centre (CPAS/OCMW) and regional loans. The welfare centre can obtain a bank guarantee for you. The Regions offer interest-free loans: the Brussels Housing Fund (a 0 % loan or the BRU-GAL fund), the Walloon social credit company SWCS (a zero-rate loan) and, in Flanders, the Vlaams Woningfonds (huurwaarborglening). A landlord who rejects you solely because the deposit runs through the welfare centre is guilty of discrimination on the ground of wealth.

Documented income. Two salaries added together, three years of rent payments with receipts, a reference from your previous landlord: that often weighs more than a guarantor the owner has never met.

Talking to the owner directly. On a peer-to-peer rental site with no intermediary, such as Domilinko, where owners' identity and each listing's energy performance certificate (EPC) are verified, you deal directly with the person who decides: the right place to explain your situation and propose one of the options above instead of a guarantor.

What to refuse: paying several months' rent in advance "instead of" a deposit. It circumvents the legal cap on the rental deposit and leaves you without recourse if the landlord returns nothing.

Three questions before signing (guarantor's side)

Signing for someone you love is a legitimate decision. Signing without knowing what you are signing is not.

Official sources

• Civil Code, Book 9 on securities (eJustice, in French): the suretyship rules in force since 1 January 2026.
• Security deposit (be.brussels): the personal guarantee among the five Brussels forms.
• Huurwaarborg (Vlaanderen.be, in Dutch): deposit and personal guarantee in Flanders.
• Walloon decree on residential leases (Wallex, in French): rental deposit and the surety's undertaking in Wallonia.
• Discrimination on the basis of wealth (Unia): when refusing someone over their income or welfare support is unlawful.
• Rental guarantee support (Brussels Housing Fund): interest-free loan and the BRU-GAL fund.