The criteria that matter for long-term investing are different from those for active trading. Custody costs, dividend handling, tax reporting quality, and the broker's own financial stability are what compound over a decade — not the trading commission.
Annual depot / custody fee
Dividend reinvestment option
ETF savings plan availability
Tax reporting quality
Account security & insurance
Financial stability of the broker
What matters most for a long-term investing broker?
For buy-and-hold investors, the annual custody cost often matters more than the trading commission — because you're paying it every year on a growing portfolio, not just when you transact. After that: dividend reinvestment options, the quality of tax reporting (which compounds over years), and the broker's own financial stability. A broker that closes or gets acquired mid-decade creates real disruption.
Is it safe to leave a large portfolio at one broker for years?
European regulations require client assets to be held in segregated accounts — they're legally separate from the broker's own funds and are protected if the broker becomes insolvent. Investor compensation schemes (up to €20,000 in the EU, £85,000 in the UK) add a second layer. What isn't covered is market loss — those protections are about broker failure, not investment performance.
How important is tax reporting for long-term investors?
Very important — and it compounds. A broker that produces accurate, easily importable tax documents saves significant time annually and reduces the risk of errors that attract attention on self-assessment returns. In Germany especially, where the handling of Vorabpauschale (ETF pre-tax) and Kapitalertragsteuer has to be correct, broker-quality tax reporting is a practical, recurring cost of ownership.
