The Premium for Locking: £60 on £20,000
Let's put the certainty tax in pounds. The best one-year fix — GB Bank or MBNA at 4.85%, per MoneySavingExpert — pays 0.30 percentage points more than Cynergy's top easy-access rate of 4.55%. That is £60 a year on £20,000, or £150 on £50,000.
And that top easy-access rate is not some compromise. It is a variable rate from an authorised, FSCS-protected bank, available on balances up to £1 million, with unlimited withdrawals. The fuss-free option, Oxbury, pays 4.33% with no bonus games at all — still only 52 basis points below the fix.
So what exactly are you buying with those £60? Protection against one specific outcome: that the Bank of England cuts rates, and cuts them fast enough, that your flexible rate falls below the 4.85% you could have locked. That is a real scenario. It is not the only scenario, and it is not the one the Bank itself is currently signalling.