I cashed enough of mine in to give me £1000 per year interest in a easy-ish access account.
If I decide to move the rest it will be to a fixed rate ISA to keep that tax free too.
Way to go imo.
NS&I make money simply by keeping their expected rate of return (not guaranteed on an individual investor basis) well below prevailing market rates.
Currently 3.15% vs 4.45% (Close Brothers 5 year FRB).
As pointed out by
@Mo1959 upthread there are some good rates on shorter terms too.
We are just about to open a new FRB with the aforementioned Close Brothers. Not 50k but fairly chunky.
At 50k our guaranteed interest would be £11125.
Obviously across 5 years you will need to do better than that with PB'S to be in front. Not impossible but unlikely.
But, more likely, you could hit the average predicted return of 3.15% every year giving a cash return of £7875. A loss of £3250 vs the FRB.
Or you could win nothing and be £11125 out of pocket.
Not a good proposition for me although I accept that some people may be happy to play the gamble.