I don't need credit, but I want to keep my credit score as high as possible, for when I might want a mortgage or come across a credit card with nice rewards.
I got a credit card with a borrowing limit of £500 and most places online say that you need to keep utilisation under 20-30%, but keeping it in the single digits (but not 0) is even better.
So, what is the lowest utilisation rate that allows me to build credit? Is something like 1% good enough?