I think that's a good scenario for a retainer. You have a long term maintenance relationship set up that typically doesn't require chunks of work at a time.
The overheads to doing a 10 minute fix are massive: they email/call you to make a request, you change work contexts, fix the issue, test and release it, notify them that you're done, keep track of the time you spent working, send an invoice at the end of the month, keep an eye out for payment, thank them for paying etc.
Rounding up to the hour mitigates this, but unless you're doing several maintenance requests per client per week, or are charging very high ($250+) hourly rates, your business is probably losing money by keeping this client on the books.
I think it's better to negotiate a monthly retainer that ensures making tiny updates is worth your while, and then just have a set-and-forget invoice that gets sent automatically every month for that amount. Even better if you can get paid by direct debit.
The overheads to doing a 10 minute fix are massive: they email/call you to make a request, you change work contexts, fix the issue, test and release it, notify them that you're done, keep track of the time you spent working, send an invoice at the end of the month, keep an eye out for payment, thank them for paying etc.
Rounding up to the hour mitigates this, but unless you're doing several maintenance requests per client per week, or are charging very high ($250+) hourly rates, your business is probably losing money by keeping this client on the books.
I think it's better to negotiate a monthly retainer that ensures making tiny updates is worth your while, and then just have a set-and-forget invoice that gets sent automatically every month for that amount. Even better if you can get paid by direct debit.