Two of the most popular savings products in Spain in 2026 are fixed-term deposits and money market funds. While they may seem similar—both offer returns on your money with low risk—they have significant differences that can make one a much better choice than the other depending on your situation. In this comparison, we break down everything you need to know.
What is a fixed-term deposit?
A fixed-term deposit is a banking product in which you deposit your money with a bank for an agreed-upon term (usually between 3 and 24 months) in exchange for a guaranteed fixed return. At maturity, you recover your full principal plus interest.
The key features are:
- Fixed return: You know exactly how much you’ll earn from day one.
- Guaranteed principal: the bank is obligated to return 100% of your principal.
- Deposit guarantee: protected up to €100,000 per account holder and institution by the Deposit Guarantee Fund (FGD) in Spain, or the European equivalent for banks in the EU.
- Limited liquidity: In most cases, you cannot withdraw the money before maturity without incurring a penalty.
What is a money market fund?
A money market fund is an investment fund that invests in very short-term fixed-income assets: Treasury bills, bank deposits, promissory notes, and corporate debt with maturities of less than one year. Its objective is to preserve capital and generate a return similar to the market interest rate (indexed to the €STR or short-term Euribor).
Its main features:
- Variable return: rises and falls with ECB interest rates. In 2024–2026, they have offered between 3% and 4% annually.
- Daily liquidity: You can redeem your shares on any business day, with funds typically available within 24–48 hours.
- No deposit guarantee: they are not covered by the Deposit Guarantee Fund (FGD), although the probability of loss is very low given the type of assets in their portfolio.
- Tax advantage for transfers: You can move money between funds tax-free until you redeem your shares permanently.
Direct comparison: deposit vs. money market fund
| Criterion | Fixed-term deposit | Money market fund |
|---|---|---|
| Return | Fixed and guaranteed from the start | Variable, tracks ECB rates |
| Principal guaranteed | Yes, 100% | Not guaranteed (minimal risk) |
| FGD guarantee | Up to €100,000 per institution | Not applicable |
| Liquidity | At maturity (or with penalty) | Daily (D+1 or D+2) |
| Minimum amount | Usually starting at €1,000 | Starting at €1 with many fund managers |
| Taxation | Taxed as capital gains upon maturity | Taxed only upon redemption. Tax-free transfer |
| Risk | Very low (bank guarantee + FGD) | Very low (ultra-short-term assets) |
| Impact of ECB interest rates | No effect once purchased | Direct: if rates fall, returns fall |
Tax differences: a crucial point
Both are taxed under personal income tax as investment income (savings base), with rates of 19% up to €6,000, 21% from €6,000 to €50,000, and 23% above €50,000.
The difference lies in timing and flexibility:
- Deposit: You pay taxes in the tax year in which interest is paid (usually at maturity). No option to defer.
- Money market fund: You are taxed only when you redeem. If you transfer the money to another fund, there is no taxable event. This allows you to defer taxation indefinitely as long as you keep the money invested in funds.
For large amounts or investors seeking tax optimization, the advantage of a money market fund can be significant.
When is a fixed-term deposit the best option?
- You want absolute certainty of returns from day one.
- You have a clear need for liquidity (you know you won’t need the money until maturity).
- You prefer the protection of the Deposit Guarantee Fund (FGD) in any scenario.
- The deposits available on the market offer a positive spread over equivalent money market funds.
- Your total amount per institution does not exceed €100,000.
When is a money market fund the best choice?
- You need flexible liquidity: you don’t know exactly when you’ll need the money.
- You want to be able to switch to other funds tax-free when interest rates change.
- You have amounts exceeding €100,000 and want to diversify your risk across institutions.
- Interest rates are rising, and you’d rather not be locked into a low fixed return.
- You prioritize tax optimization and plan to hold the investment for several years.
Practical example with €20,000 in 2026
Suppose you invest €20,000. With a 12-month deposit at 2.5% APR, you earn €500 gross after one year. You’ll pay 19% income tax on that €500 = €95, leaving you with €405 net.
With a money market fund at 3.2% APR (variable) that same year, you earn approximately €640 gross. If you transfer it to another fund, you pay no taxes that year. If you redeem it, you pay 19% on the capital gains: €518 net.
However: if ECB rates fall over the course of the year (as happened in 2024–2025), the fund’s return may end up being lower than that of the deposit you set at the start.
Conclusion
There is no one-size-fits-all winner. The fixed-term deposit wins in terms of perceived security, simplicity, and certainty. The money market fund wins in terms of liquidity, flexibility, and tax advantages for long-term investors.
On APYData, you can compare the best available deposits and the most profitable money market funds on the market in real time, with data updated daily.