Write the next one down.
Five free, and the other person never pays.
For friends and family
Every small favour, loan and promise that everybody means at the time and nobody writes down. Then it is eight months later and asking feels rude.
The awkwardness is the problem
Nobody wants to be the person chasing their own sister for forty pounds. So it does not get chased, and it quietly turns into something you think about every time you see them.
A written agreement takes the chasing off you. It was agreed, in their words, and a reminder asks the question instead.
“I’ll bring the dessert on Saturday”
Occasions
Christmas, birthdays, the family meal where three people bring a trifle and nobody brings chairs.
One agreement each, answered in seconds from a link. Nobody installs anything, which matters when the person you are asking is your gran.
Money between friends
For anything with a number on it you can ask for a signature. It is not a contract, and we say so plainly. What a signature here means.
Five free, and the other person never pays.