Guarantor (Fiador) Requirements in Portugal: Legal Rules and Best Practices

A fiador (guarantor) is a third party who secures the tenant's obligations and becomes personally bound to the landlord as creditor. Art. 627º of the Civil Code defines this accessory guarantee (*fiança*). A guarantor is not legally mandatory for a residential lease, but landlords commonly request one.

The signed guarantee must identify its scope and duration clearly. Definition of the guarantee, the default excussion benefit, a valid waiver, and the lease-specific arrears notice are separate rules; no single article should be used as shorthand for all four.

Under Art. 638º, a guarantor may, subject to the statutory conditions, refuse performance while the creditor has not pursued the debtor's assets without obtaining satisfaction. This is the benefit of excussion (*benefício de excussão*).

The practical effect depends on the signed guarantee and the enforcement facts. Do not assume either that every guarantor has waived the benefit or that naming someone a fiador automatically makes them a principal payer.

Art. 640º addresses exclusion of the excussion benefits, including where the guarantor has waived excussion or assumed the position of principal payer (*principal pagador*). A valid waiver can remove the need to pursue the tenant's assets first, but it does not erase the separate arrears-notice gate for leases.

Under Art. 1041º n.os 5–6, if the tenant does not cure the default within the statutory eight-day period, the landlord must notify the guarantor of the default and sums due within the following 90 days. The landlord may demand satisfaction from the guarantor only after that notice. Preserve the signed guarantee, the tenant-default timeline, the notice content and proof of delivery.