Locking money away for a fixed period usually earns a better rate than leaving it accessible. The premium is payment for a specific thing the saver has surrendered.
Certainty is what the bank is buying
A bank lends over long periods and funds itself with deposits that can leave at any moment, which creates a permanent mismatch it has to manage.
Money committed for a known term removes part of that uncertainty, allowing the bank to plan its funding and hold less liquidity in reserve against sudden withdrawals.
The higher rate is the price of that certainty, which is why it is paid for the commitment itself rather than for the size of the balance.
The curve is a forecast, not a reward ladder
Savers often assume longer terms always pay more, but the relationship reflects expectations about future rates rather than a fixed premium for patience.
When rates are expected to fall, banks will pay less for long commitments than short ones, because they do not want to be locked into paying today's rate for years.
A shorter term paying more than a longer one is therefore a signal about what the market anticipates, and it appears regularly rather than as an anomaly.
Early access is deliberately expensive
Breaking a term deposit typically costs a defined number of days of interest, and some products do not permit early access at all.
The penalty exists because early withdrawal returns exactly the uncertainty the bank paid to remove, so allowing it freely would eliminate the reason for the higher rate.
Where the penalty exceeds interest already earned, the saver can receive back less than was deposited, which is the case people are most often unaware of.
Reinvestment risk sits at maturity
A fixed rate protects against falling rates during the term, but when the term ends the money must be reinvested at whatever rates then exist.
A saver rolling a series of short deposits captures rising rates quickly and suffers immediately when rates fall, while a long fixed term does the reverse.
Splitting a balance across staggered maturities means a portion reprices each year, which moderates both effects without requiring a view on where rates are heading.
Maturity handling deserves attention
Many products roll automatically into a new term if no instruction is given, and the replacement rate is frequently well below what is available elsewhere.
Some institutions instead move matured funds into an instant access account paying very little, where balances can sit unnoticed for long periods.
Because both outcomes are automatic, the maturity date is worth recording separately rather than relying on the institution to prompt a decision.