To send a registered letter with acknowledgement of receipt in Portugal, prepare the document and the envelope, confirm the recipient’s identity and address, choose Registered Mail (Correio Registado) and add the “Proof of Delivery (Acknowledgement of Receipt)” service. Keep a signed copy of the letter, the acceptance slip, the tracking code and the returned acknowledgement. In a tenancy, this chain of proof can be as important as the text of the notice itself.
- Registered mail: creates a record of acceptance and lets you track the item.
- Acknowledgement of receipt: adds a signed proof of delivery at the address.
- Electronic notice: informs you by SMS or email, but CTT (Portugal’s postal service) make clear it does not replace the proof of delivery as evidence in court.
- For sensitive tenancy notices, check whether the law requires a specific form, recipient, address or notice period.
How to send a registered letter: step by step
- Write a complete notice. Identify the sender, recipient, lease or property, facts, request, deadline and date.
- Confirm a valid address. In a tenancy, use the address provided for in the lease and check the specific rules for the notice.
- Sign it and make a copy. The copy you keep must be exactly the same as the one that goes in the envelope.
- Choose Registered Mail. Ask for the service level that suits the content and the destination.
- Add Acknowledgement of Receipt. Ask for the “Proof of Delivery” when you need signed evidence of delivery.
- Keep the slip and the tracking code. Photograph or scan it before the thermal print fades.
- File the result. Add the letter, annexes, proof of acceptance, tracking and acknowledgement of receipt to the tenancy file.
Registered letter, acknowledgement of receipt and electronic notice
| Option | What it shows | When to use |
|---|---|---|
| Ordinary mail | Does not create a comparable chain of proof | Notices with no relevant legal consequence |
| Registered mail | Acceptance of the item and tracking | When you need to prove you sent the letter |
| Registered with acknowledgement of receipt | Acceptance, tracking and signed proof of delivery | Sensitive contractual or legal notices |
| Electronic notice | An alert of where and when the item was delivered | An operational extra; CTT say it does not serve as proof in court |
| Delivery to the addressee in person | Delivery restricted to the identified recipient | When the identity of the person receiving it is critical; requires acknowledgement of receipt |
When should you use a registered letter in a tenancy?
Article 9 of the NRAU (the New Urban Lease Regime) provides for written form for legally required communications between landlord and tenant concerning, among other things, termination of the lease, rent updates and works. The applicable rule varies with the type of notice and the circumstances; so it is not enough to choose “registered” — you must respect the content, the address, the recipient and the deadline.
Among the most frequent cases are:
- notifying the annual rent update;
- formally demanding payment of overdue rent;
- notifying repeated breaches;
- giving notice of opposition to renewal, termination or termination for breach;
- dealing with works, access to the property or restoring conditions;
- requesting or replying about the return of the deposit.
If rent is unpaid, start by organising the timeline of the arrears. For termination, see the termination letter. If you want to update the rent, use the rent update letter.
Is it possible to send a registered letter without going to the post office?
There are services that prepare, print and route correspondence from a digital request. Before using any provider, confirm who the sender is, what proof you receive, how tracking is done, how long the documents stay available and how personal data is handled.
For a landlord, the ideal flow is simple: choose the right notice within the tenancy, fill in the lease details automatically, review the PDF, confirm the address and keep the proof with the property’s history. This avoids the most common mistake of generic services: a letter that is sent but disconnected from the deadline and the process that justify it.
Checklist before confirming dispatch
- Do the recipient’s name and address match the lease?
- Does the letter clearly identify the property and the parties?
- Are the grounds, amount and dates correct?
- Was the notice period calculated from the applicable rule?
- Are the annexes mentioned really in the envelope?
- Have you kept a final, non-editable version?
- Did you choose acknowledgement of receipt if you need signed proof of delivery?
- Have you set a reminder to check the tracking and the reply?
What should you keep as proof?
On Aluseg, letters start from the lease data, stay linked to the property and can go through the registered-mail flow when it is available for your account.
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Frequently asked questions
What is a registered letter with acknowledgement of receipt?
It is a Registered Mail item to which a signed proof of delivery is added. You get proof of acceptance, tracking and an additional record of delivery at the address.
Is acknowledgement of receipt always compulsory?
Not for all correspondence. Use it when the applicable rule or the risk of the situation justifies signed proof of delivery. In a tenancy, check the regime for the specific notice.
Does a text message from CTT count as proof in court?
CTT distinguish the electronic notice from the Proof of Delivery and state that the SMS or email alert cannot be used as proof in court.
Can I send a registered letter online?
You can use a service that handles printing and dispatch, but you must confirm who sends it, what proof you receive, how you track the item and how data and documents are protected.
Which address should I use to contact the tenant?
The answer depends on the lease, the notice and the NRAU rules. Check the agreed address and the legal requirements before sending a notification with contractual effects.
What happens if the letter is returned?
Keep the sealed envelope, the tracking and all postal markings. The legal consequence depends on the reason for the return and the applicable rule; get advice before repeating the notice or changing the means of communication.
Official sources consulted: CTT — Registered Mail and additional services; Law no. 6/2006, article 9 (NRAU). Updated on 12 September 2026.
