What is self-certification of illness and how do you request it?

There are times when your health demands a break, even if only for a short while. The good news is that, in cases of illness, you can justify up to three days of absence from work without a medical certificate, by using the Self-Certification of Illness (Autodeclaração de Doença, ADD).
Read on to find out how it works, how to request it and what other useful features you can find on the SNS 24 Portal and the SNS 24 App.
Self-certification of illness: what it is
Self-certification of illness – also known as “self sick leave” – is a simple, practical mechanism designed for short-term illness. Without needing to travel to the doctor or health centre, the worker can justify up to three consecutive days of absence due to illness, declaring it on their honour.
This system, available to those aged over 16, allows you to justify absences up to twice a year, totalling six days of sick leave per calendar year (using two periods of three days each). It is especially useful for dealing with mild flu, passing ailments or other situations that do not require immediate medical attention.
And even if you only need to be absent for a single day, you can request a one-day self-certification of illness.
When should I request my self-certification?
You should request the self-certification of illness within five days of the start of your absence. Please note: as mentioned, you may only use it twice a year, with a maximum of three consecutive days per request.
How do you obtain the self-certification of illness document?
There are three very simple ways to request the three-day sick leave, online or by phone. Take a look:
Requesting the self-certification of illness on the SNS 24 Portal
- Go to the SNS 24 Portal
- Log in with your Chave Móvel Digital (Digital Mobile Key), Citizen Card or patient number
- Click on “Self-Certification of Illness”
- Enter the start date of your illness
- Confirm the details and submit the request.
You will receive a code that you can share with your employer.
Requesting the self-certification of illness on the SNS 24 App
- Install the SNS 24 App on your phone
- Follow the same steps as on the portal to make the request.
Requesting the self-certification of illness on the SNS 24 App
If you prefer to speak to someone, you can call 808 24 24 24 and request the ADD with the help of an operator.
How do you validate the self-certification of illness?
You can view and validate the self-certification quite easily:
- On the SNS 24 Portal: go to your personal area and check your request history
- On the SNS 24 App: the code will be available in your account
- By SMS or email: use the confirmation message you received
- Via the SNS 24 Line: call 808 24 24 24.
Give the validation code to your employer, who will be able to confirm its authenticity on the SNS 24 Portal.
Other SNS 24 features
Self-certification of illness is just one of the many conveniences offered by SNS 24. On the portal and app, you can:
- Book appointments at your health centre or paediatric appointments
- Access your digital vaccination record
- View test and examination results
- Renew medical prescriptions.
Other SNS 24 features
- Limitations: remember that the ADD can only be used twice a year and is unpaid. After the three days, if you are still ill, you will need to obtain a medical certificate
- How to share the code: as soon as you issue the self-certification, send the code you received to your employer. The employer can confirm its authenticity on the SNS 24 Portal
- Use it responsibly: the ADD is a practical but limited resource. Save it for situations where you truly need it.
Your health comes first
Do you need to travel to an appointment or examination and have no transport? Don’t worry, count on Ambula! We take care of the transport with complete safety and comfort.
Need non-emergency patient transport?
Ambula handles everything — with comfort, punctuality and care.
Book a transport