Letras del Tesoro are Spanish government debt at 3, 6, 9 or 12 months, from €1,000, bought at a discount at auction and repaid at face value on maturity. At the latest auction (September 8, 2026) the 12-month bill yielded 2.832 % a year. Here you have the calculator net of fees and tax, the three ways to buy them and how they are taxed.
Treasury data checked on September 25, 2026 · Links to Freedom24 are affiliate links
The three keys
Source: tesoro.es (results of the September 8, 2026 auction) and Bank of Spain (direct account tariffs). Checked on 25 September 2026.
Results published by the Spanish Treasury for the September 8, 2026 auction (the 6-month bill, 1 September). The average yield is what you get when you bid without a price (non-competitive bid), which is what a retail investor does.
| Maturity | Average annual yield | Average price | Gain per €1,000 |
|---|---|---|---|
| 3 months | 2.456 % | 99.431 % | 5.69 € |
| 6 months | 2.623 % | 98.692 % | 13.08 € |
| 9 months | 2.776 % | 97.990 % | 20.10 € |
| 12 months | 2.832 % | 97.163 % | 28.37 € |
Gross gain at maturity per €1,000 of face value: it is what you pay less when buying. The Treasury’s annual yield is calculated on a 360-day basis.
There are usually two a month: first the 6- and 12-month bills, then the 3- and 9-month ones. Bids are submitted up to the day before; results are out the same day.
Official Treasury calendarThe auction yield is gross. Here you see what you pay, what you receive and what the Bank of Spain fee and the tax office take, against leaving the same money in a savings account for the same time.
Gross yield
2.83 %
a year
The one the Treasury publishes: (face value / price − 1) × 360 / days.
Net yield
2.17 %
a year
After the fee and your income tax, annualised the same way.
You pay today
€9,716.30
Gross gain
€283.70
Bank of Spain fee
€15.00
Income tax
€51.05
Bill versus savings account · over 12 months
The bill leaves you €55.43 more than the account over 12 months, with fee and tax already deducted from both.
Assumptions: bought at auction at the stated price and held to maturity; Bank of Spain fee on the face value at repayment; income tax on the gain minus the fee; the savings account pays simple interest for the same days and is taxed the same way. A broker or bank will charge its own fees. This is not tax advice.
Bills are issued at auction and any individual can take part with a non-competitive bid: you ask for an amount and are allotted at the average price. What changes between the three routes is the fee and the convenience.
You open a securities account in your name at any Bank of Spain branch (by appointment) and buy at each auction from there. It is the traditional route and the cheapest.
No purchase or custody fee; 0.15% on repayment (min. €0.90, max. €200)
The Treasury’s securities trading service lets you buy from home with a digital certificate, electronic ID or Cl@ve. It uses the same Bank of Spain direct account, so there is no need to visit a branch.
Same Bank of Spain tariff; no added cost
Most banks and some brokers place the bid for you and hold the bills in custody. Convenient if you are already a client, but each firm applies its own purchase and custody fees, and on short-term bills they weigh heavily.
Each firm’s own fees: compare them with the yield
Appointment at the Bank of Spain with your ID and a bank account in your name for payments, or online registration at tesoro.es with a digital certificate or Cl@ve.
Check the calendar: 3 and 9 months or 6 and 12 months, twice a month. Decide how long you can do without the money.
Non-competitive, for the face value you want (multiples of €1,000), up to the day before the auction. You are allotted at the average price and the amount is debited.
On the maturity date you receive the full face value in your bank account, minus the 0.15% transfer fee. You can reinvest it at the next auction.
Bills trade on the secondary market and can be sold before maturity through a financial institution, but at market price and with fees; if you may need the money earlier, choose a shorter maturity.
The gain (face value minus price paid) is investment income. Three things worth knowing before the tax return.
At 19% up to €6,000 of savings income a year, 21% up to €50,000, 23% up to €200,000, 27% up to €300,000 and 30% above that (AEAT 2025 tax return manual).
Nothing is withheld on repayment. It is a financial advantage, but it means checking that the gain appears in the draft return for the year of maturity and adding it if it is missing.
A bill bought in October and repaid the following October is taxed in the return for that second year. The Bank of Spain fee is an expense of the transaction.
Scale and treatment under Spanish income tax law and the AEAT 2025 tax return manual. Every case is different: for specific questions, consult a tax adviser.
All four are for money you do not want to risk in the stock market, but they are not interchangeable. What separates them is the term, who is liable and what it costs to get out.
| Treasury bill | Savings account | Deposit | Bond | |
|---|---|---|---|---|
| Term | 3 to 12 months | No term | 3 months to 3 years | 2 to 30 years |
| Who is liable | The State | The bank; deposit guarantee up to €100,000 if a Spanish bank | The bank; deposit guarantee up to €100,000 | The issuer (government or company) |
| Getting out early | Selling on the market, with a fee | Immediate | Penalty or not allowed | Selling on the market, with price risk |
| Withholding | None; savings base | 19% on payment; savings base | 19% on payment; savings base | 19% on coupons; savings base |
| What for | Money you will not need for a year, at a locked rate | Emergency fund and money waiting | Fixed-term savings at your bank | Fixed income over years, with a coupon |
Indicative table. Account and deposit rates change with ECB rates; the bill’s is fixed at auction.
The bill covers money for under a year. For longer terms we use Freedom24: government and corporate bonds from €1,000.
Affiliate link: if you open an account, Freedom24 pays us a commission at no cost to you. Freedom24 data are from its official website.
When fear rules, the bill is the refuge everyone looks for; when greed rules, it is forgotten. The rate it locks in today is worth the same either way.
Source: CNN Business Fear & Greed Index. Updated once a day at 22:30 CET, Monday to Friday, after the US market close — when the day’s reading is final.
See today’s marketThe bill’s yield follows the ECB rate, and what you really keep is that yield minus inflation. These two figures, kept up to date, tell you whether the bill preserves or loses purchasing power.
Fixed income today
4,07 %
Spain 10-year government debt
The benchmark for what long-term fixed income yields: coupons on similar bonds move with it.
Reading for October 2026 · BCE
Your cash, earning interest
2,63 %
3-month Euribor
ECB deposit facility2,5 %
Roughly what your uninvested money earns in a euro savings account while you wait for the right moment.
Reading for October 2026 · BCE (Refinitiv)
The inflation to beat
2,9 %
Annual CPI (Spain)
Your coupon only gains purchasing power if it beats inflation.
Reading for December 2025 · INE
Official data from their sources (ECB and INE) with their date. The calculator above does not deduct inflation: subtract it yourself from the net yield.
Want to lock in a rate for more than a year? Coupons, yield to maturity and where to buy bonds, in our guide.
How to invest in bondsWhat if, instead of fixed income, you invested for the long term? Check it with the compound interest calculator.
Compound interest calculatorShort-term Spanish government debt (3, 6, 9 or 12 months), issued at a discount: you pay less than €1,000 per bill and receive €1,000 at maturity. The difference is your return. They are bought at auction with a minimum bid of €1,000.
At the latest auction (8 September 2026) the average yield was 2.456% at 3 months, 2.623% at 6, 2.776% at 9 and 2.832% at 12 months, gross. With €10,000 at 12 months you pay about €9,716 and receive €10,000: €283.70 gross, which after a €15 fee and 19% income tax comes to about €218 net.
Open a direct account at the Bank of Spain (by appointment) or register for the trading service at tesoro.es with a digital certificate or Cl@ve, and submit a non-competitive bid before the auction. Also through your bank or broker, with their fees.
At the Bank of Spain, no purchase or custody fee: only 0.15% on the amount transferred to you at maturity, with a minimum of €0.90 and a maximum of €200. Banks and brokers charge their own, which on short maturities can eat a good part of the yield.
The gain is taxed in the savings base of Spanish income tax (19% up to €6,000, then 21, 23, 27 and 30%) in the year of maturity. There is no withholding, so check that the gain is in the draft return and add it if it is not.
Yes, they trade on the secondary market and can be sold through a financial institution, at market price and with fees. If you think you will need the money, it is better to choose the 3- or 6-month maturity.
They are backed by the Spanish State, the most creditworthy borrower a retail saver can lend to in euros. The real risk is opportunity: if rates rise after the auction, your bill lags until maturity; if inflation exceeds the yield, you lose purchasing power.
The bill locks the rate for months and has no withholding; the savings account is instantly liquid but its rate changes with the ECB and 19% is withheld on payment. For the emergency fund, the account; for money you will not touch for a year, the bill. The calculator above compares both net.
Work out your bill net, buy where you are not overcharged and, for money going beyond a year, look at bonds.
Disclosure: links to Freedom24 are affiliate links; if you open an account, Freedom24 pays us a commission at no cost to you. Spanish Treasury bills are bought at the Bank of Spain or tesoro.es, with which we have no commercial relationship. Data are those published by the Spanish Treasury and the Bank of Spain on the dates stated.
Educational content. It is not financial or tax advice. All investing carries risk.