This is such a first world problem, but what is it with companies making people dig out a random numerical username to do anything?
I just went to pay my council tax and was told I'd need my username, a random 10 digit number that they have posted to me. Turned a 5 minute job into a 30 minute one, as I had to wait on the phone to them for ages to sort it.
Email address, house address etc not good enough - it's not like someone is going to hack me to pay my council tax? They'd be welcome to do so.
The same thing with UCAS last week - you need your email address and a random numerical username to log in, which they send you in one email when you sign up. It just seems so unnecessary and annoying?