All the Cases Where Portugal Requires a Registered Letter with AR

In Portugal, the registered letter with aviso de receção (AR, the signed proof-of-delivery slip returned to the sender) is far more than a bureaucratic formality. There is a broad set of situations, in tenancies, commercial contracts, debt collection, insurance, employment and beyond, where Portuguese law expressly requires this form of communication. Using any other channel can make the notice legally invalid. If you own property, run a business or hold contracts in Portugal, even from abroad, these rules apply to you.

This article gathers the main cases where sending a registered letter with AR is legally required, plus the cases where, even without an express obligation, it is strongly recommended.

Cases where it is legally required

Residential and urban tenancies

The NRAU (Novo Regime do Arrendamento Urbano, the Portuguese urban lease law) and the Código Civil (the Portuguese Civil Code) prescribe the registered letter with AR for several landlord-tenant communications:

Service and supply contracts

Many contracts between individuals or companies include clauses making the registered letter with AR the exclusive channel for significant acts: termination, non-renewal, breach. Even where the contract does not expressly require it, the registered letter with AR is the safest way to exercise rights when a dispute is a possibility.

Typical cases: terminating maintenance contracts, IT service agreements, condominium management contracts, commercial exclusivity agreements.

Out-of-court debt collection

Before going to court or handing a debt to a recovery agency, the debtor must be notified in writing. The registered letter with AR serves as the formal out-of-court demand ("interpelação") and is frequently required by Portuguese courts as a condition for claiming costs or default interest. Without it, the debtor can claim they were never notified.

Employment

The Portuguese Labour Code (Código do Trabalho) requires written form for several acts, and the registered letter with AR is the channel that guarantees proof of receipt. The most common cases:

• Dismissal for just cause: the communication to the employee must be in writing, delivered by hand or by registered letter with AR
• Preventive suspension of an employee
• Notice of disciplinary proceedings
• Resignation with just cause by the employee

Insurance

The Portuguese Insurance Contract Law (Decree-Law no. 72/2008) provides situations where the insurer or the policyholder must communicate by registered letter with AR:

• Termination of the insurance contract by either party
• Notice of aggravated risk
• Opposition to automatic renewal of the contract
• Formal claim notification in some types of cover

Condominiums

Notices convening condominium owners' meetings must be sent by registered letter or with aviso de receção where some owners do not live in the building (article 1432.º of the Código Civil). Communications about urgent works and formal demands to owners in arrears should also follow this channel.

Credit and financing contracts

In consumer credit and mortgage lending, the law and standard contracts require a registered letter with AR for significant formal communications, notably withdrawal letters, early termination of the contract, and default notices.

Cases where it is recommended, but not required

There are situations where the law does not expressly impose the registered letter with AR, but where using it is strongly recommended for practical reasons:

• Cancelling telecoms or subscription contracts: standard contracts accept written notice, but the registered letter with AR is the safest way to prove the exact cancellation date
• Reporting defects in building work or services: to trigger warranties or civil liability, you want proof that the supplier was notified
• Rescinding purchase contracts over defective goods: when the seller does not respond, the registered letter with AR starts the legal clock
• Communications to public bodies where deadlines are running: whenever a legal deadline is at stake, the registered letter with AR fixes the sending date beyond dispute
• Agreements between heirs or co-owners of assets: formal demands that may later matter in estate divisions or disputes

What happens if you skip it when it is required

The consequences vary by context, but they are generally serious:

• The communication is invalid: as if it had never been made. Deadlines do not start running, and the recipient is not in default.
• The court case can be dismissed: courts require proof of prior notification. Without the letter with AR, the judge can reject the claim outright.
• Loss of rights: in tenancies, for example, a rent update sent without a registered letter with AR may not be enforceable against the tenant.
• Civil liability: in employment or contract matters, a termination made without the required form can be deemed unlawful and give rise to compensation.

How to send a registered letter with AR

There are two main routes:

At a CTT post office (CTT is the Portuguese postal service): write the letter, print it, travel to a CTT post office in Portugal, pay for registered mail with AR (around €6.05) and wait for the aviso de receção signed by the recipient to come back by post. It requires being in Portugal and free during counter hours.

Online, without leaving home: through cartaregistada.pt, upload the letter you prepared, enter the recipient's details, and we handle the CTT sending with aviso de receção, lodging the letter within 2 business days. No queues, no travel, no need to be in Portugal. The whole process takes less than 5 minutes and costs €14.99.