Best Online Brokers in Spain 2026

What to check before choosing a broker in Spain

Spain has a well-regulated investment environment under CNMV supervision and a straightforward capital gains tax framework. Spanish investors benefit from FOGAIN investor protection up to €100,000 — significantly above the EU minimum. The key tax consideration is the progressive savings tax base (base imponible del ahorro) and Modelo 720 reporting obligations for foreign accounts.

1. CNMV authorisation is mandatory. All brokers serving Spanish retail investors must be authorised by the CNMV (Comisión Nacional del Mercado de Valores) — Spain's securities market regulator — or operate under EU MiFID II passporting. The Banco de España also supervises banks that provide investment services. Verify broker authorisation at cnmv.es. The CNMV also maintains a list of unauthorised/fraudulent operators (chiringuitos financieros).

2. Capital gains taxed in the base del ahorro at progressive rates. Spain taxes investment income (capital gains, dividends, interest) in the base imponible del ahorro (savings tax base) using progressive rates. Since 2023: 19% on the first €6,000; 21% on €6,001–€50,000; 23% on €50,001–€200,000; 27% on €200,001–€300,000; and 28% on gains above €300,000. These rates apply to all investment income equally — there is no distinction between short-term and long-term holdings.

3. Modelo 720 for foreign accounts. Spanish tax residents holding assets abroad (financial accounts, real estate, insurance) exceeding €50,000 per category must file Modelo 720 with the AEAT (Agencia Estatal de Administración Tributaria). Failure to file carries severe penalties (historically up to 150% of the value of the undeclared asset, though the Constitutional Court partially struck down these sanctions in 2022). You must also file Modelo 721 for cryptocurrencies held at foreign platforms exceeding €50,000 (from 2023). This is critical for Spanish residents using DEGIRO, Interactive Brokers, or other foreign brokers.

4. Loss carry-forward and compensation rules. Capital losses can be offset against capital gains in the same year. Remaining losses can be carried forward for 4 years to offset future gains. There is a limit on offsetting capital losses from asset sales against investment income (interest, dividends) — a maximum of 25% can be offset. Understanding these compensation rules is essential for tax-efficient portfolio rebalancing in Spain.

What Spanish Investors Need to Know in 2026

The fondos de inversión traspaso benefit is Spain's most powerful (and often overlooked) tax advantage. By investing in qualifying UCITS mutual funds rather than ETFs, Spanish investors can rebalance their portfolio indefinitely without triggering capital gains tax. This is equivalent to a partial tax deferral on portfolio growth — a meaningful advantage over a long investment horizon.

Modelo 720 compliance is critical. The Constitutional Court's 2022 ruling reduced the penalty structure, but the reporting obligation remains. Spanish residents with foreign broker accounts (DEGIRO, Interactive Brokers, Revolut) must carefully track balances throughout the year. Since 2023, Modelo 721 adds a parallel obligation for crypto assets at foreign exchanges.

The IBEX 35 is Spain's flagship index, but most Spanish investors seeking global diversification invest through low-cost UCITS ETFs or mutual funds tracking MSCI World or MSCI All Country World. Interactive Brokers provides the best combination of global access, low fees, and comprehensive tax reporting documentation for the Declaración de la Renta.