An annuity pays a level income that does not increase; you may be concerned that as time goes by the real value of your income may be eroded by the effects of inflation. However, you can choose to have your pension income increase each year. But the amount you will initially receive will be lower than one which does not increase. It is possible to choose the level of increase at outset; typically 3%, 5% or RPI linked (inflation).
This is generally considered an expensive option because of the impact of the starting income. It can take many years before you break even.
Source: Iress – Healthy Male Annuity for £50,000 on 31.7.2023.