Deposit Rates Shrink After Tax and Short Terms

That distinction is economically important for households because deposit income is a function of both rate and duration, not just the headline number. It is also important for banks, which can use short-dated promotions to attract cash without locking in expensive funding for long periods. In a market where policy rates and deposit competition can shift quickly, banks benefit from the flexibility of rolling short-term offers while customers bear the reinvestment risk if yields fall.

The structure of the offer can be just as important as the coupon. Promotional rates often apply only to a capped amount, such as 20,000 zł or 50,000 zł, meaning larger savers may not earn the advertised rate on their full balance. Banks can also limit access to new customers, new money or customers who open a current account, use a mobile app or maintain regular inflows. Those conditions can reduce the effective yield once fees or ancillary product costs are included.

For investors and savers, that creates a simple but often overlooked trade-off: a shorter deposit offers liquidity and a chance to reprice into better rates later, while a longer one gives certainty but traps cash if market yields rise. The article’s advice to ladder deposits across three, six and 12 months reflects that tension and is widely used by households trying to manage both reinvestment and interest-rate risk.

The broader backdrop is still one of elevated but uneven interest-rate pressure. The Bank of England has held rates at 3.75% despite sticky inflation, while other central banks have remained more restrictive. In that setting, deposit promotions can look attractive, but they are not a substitute for understanding real after-tax returns. The key investor takeaway is that the highest advertised rate is not always the best outcome; the best offer is the one that maximizes net yield on the amount you can actually commit for the right length of time.