Certificados de Aforro vs Tesouro in Portugal (2026)
If you live in Portugal and want a low-risk home for savings, the two State options are Certificados de Aforro (Série F) and the new Certificados do Tesouro Série 5. In November 2026, Aforro Série F pays a base rate of 2.50% gross, the maximum its formula allows, while Tesouro Série 5 offers fixed rates that rise from 2.35% in year one to 3.35% in year ten. Both are capital-guaranteed by the Portuguese State, but they suit different savers.
This guide compares both products in plain English: how the rates work, what you keep after tax, how to buy them and which mistakes to avoid. It is general information, not financial advice; for your own situation, check with a qualified advisor in Portugal.
The short answer
- Choose Certificados de Aforro if you want flexibility, small amounts and a rate that follows Euribor (up to a cap).
- Choose Certificados do Tesouro Série 5 if you want rates fixed in advance and can leave at least €1,000 invested for several years.
- Neither product currently beats the inflation forecasts cited by consumer group DECO, so treat them as safe savings, not wealth builders.
Certificados de Aforro Série F: how they work
Certificados de Aforro are savings certificates issued by the IGCP, the Portuguese public debt agency. The current series, Série F, has been on sale since June 2023, after Série E was withdrawn.
Interest rate
The base rate is set each month from the average 3-month Euribor over the previous ten business days. It cannot go below 0% or above 2.50%. Because Euribor has been above that cap, the base rate for subscriptions was 2.50% in September, October and November 2026. For comparison, it was 2.195% in May 2026.
On top of the base rate you earn a loyalty premium (prémio de permanência) the longer you hold:
| Holding year | Premium added to base rate |
|---|---|
| Year 1 | none |
| Years 2–5 | +0.25 points |
| Years 6–9 | +0.50 points |
| Years 10–11 | +1.00 point |
| Years 12–13 | +1.50 points |
| Years 14–15 | +1.75 points |
So, with the base rate at its 2.50% cap, the gross rate could reach 4.25% in the last two years of the 15-year term.
Key conditions
- Units are worth €1 each. Your first subscription must be at least €100 (100 units); further top-ups can be from €10.
- Maximum of 250,000 units of Série F per savings account.
- Term of up to 15 years, with the capital guaranteed by the State.
- Interest is paid every three months and automatically added to your capital, already net of tax.
- You can cash out in full or in part after the first interest date. Money arrives within about seven days, but you lose the interest of the quarter in progress.
- Only individuals can hold them, one savings account (conta aforro) per person.
Certificados do Tesouro Série 5: fixed and rising
The IGCP launched Certificados do Tesouro Série 5 (CTS5) on 7 July 2026, replacing the Certificados do Tesouro Poupança Valor, which are no longer sold. Their main features:
- 10-year term with capital guaranteed.
- Fixed annual rates rising from 2.35% in year one to 3.35% in year ten.
- Interest paid once a year.
- Minimum investment of €1,000, maximum €1 million per holder.
- Early redemption possible from the end of the first year.
The appeal is predictability: you know today what you will earn every year, whatever happens to Euribor.
Side-by-side comparison
| Feature | Aforro Série F | Tesouro Série 5 |
|---|---|---|
| Rate type | Variable (Euribor), capped at 2.50% plus premium | Fixed, rising 2.35% to 3.35% |
| Minimum | €100 first subscription | €1,000 |
| Term | Up to 15 years | 10 years |
| Interest paid | Quarterly, reinvested | Annually |
| Early exit | After first quarter | After first year |
| Capital guarantee | Portuguese State | Portuguese State |
DECO’s September 2026 analysis estimated net annual returns of about 1.8% over one year, 2.0% over five years and 2.1% over ten years for Aforro Série F (assuming the 2.50% base rate holds), against 1.7%, 1.8% and 1.9% for Tesouro Série 5. It also noted that the best fixed-term bank deposit could beat both over one year, but not over five.
Tax on interest
For Certificados de Aforro, interest is subject to 28% Portuguese income tax, withheld at source each quarter. You normally do not need to declare it, unless you choose to aggregate (englobar) all your investment income in your IRS return, which can make sense for lower incomes. Tesouro certificates also pay taxable interest. Tax treatment depends on your residence and personal situation, so confirm with a qualified tax advisor in Portugal before deciding (not financial or legal advice).
How to buy, step by step
- Get a Portuguese tax number (NIF). Both products require it.
- Open a savings account (conta aforro) with the IGCP. You need ID, your NIF, proof of IBAN, address and profession.
- Make your first subscription at a CTT post office, an Espaço Cidadão, or through participating banks such as Banco BiG. The CTT app has also become an option.
- Join AforroNet, the IGCP’s online platform, to subscribe, check balances and redeem online.
- Choose the product: Aforro Série F (from €100) or Tesouro Série 5 (from €1,000).
Which one suits you?
Aforro Série F works well as an emergency fund or medium-term savings pot: low entry amount, quarterly access and a rate that will follow Euribor down as well as up. If rates fall, your return falls too, though never below 0% plus the premium.
Tesouro Série 5 is better if you want certainty and can commit for longer. Its rising fixed rates reward patience, but you cannot touch the money in the first year and the €1,000 minimum is higher.
Many savers split money between both: Aforro for flexibility, Tesouro for a locked-in rate. Neither is designed to grow wealth faster than inflation over the long run. For that, you would need to look at riskier assets, ideally with professional advice. Readers in other countries can compare similar schemes in our guides to Ireland’s State Savings and Polish Treasury bonds.
Common mistakes
- Redeeming just before an interest date. You lose the interest of the current quarter, so check your quarter dates first.
- Assuming the 2.50% is fixed. The Aforro base rate is reset monthly and will fall if Euribor drops below the cap.
- Forgetting the first-year lock on Tesouro Série 5. Do not invest money you may need within 12 months.
- Ignoring inflation. A capital guarantee protects euros, not purchasing power.
- Comparing gross with net. Bank deposit offers and certificate rates are often quoted gross; compare after the 28% tax.
FAQ
Can foreigners buy Certificados de Aforro?
You need a Portuguese NIF and a conta aforro. Tax depends on where you are resident, so non-residents should get advice before buying.
Is there a maximum on Certificados de Aforro?
Yes. Each savings account can hold up to 250,000 units of Série F (€250,000 at face value).
What happens if Euribor falls?
The Aforro base rate falls with it, with a floor of 0%. Your loyalty premium is still added on top. Tesouro Série 5 rates do not change.
Are these safer than bank deposits?
Both are guaranteed by the Portuguese State. Bank deposits are protected by the deposit guarantee scheme up to its legal limit. For most savers, both are low-risk; the difference lies in rates, access and tax.
Conclusion
In late 2026, Certificados de Aforro Série F sit at their maximum 2.50% base rate and stay the flexible choice for Portuguese savers, while Certificados do Tesouro Série 5 offer fixed, rising rates for those who can lock money away. Pick based on when you might need the money, not just the headline rate. If you are building a broader plan, our overview of high-yield savings accounts explains how safe savings fit alongside other passive income options.
