Capital is the amount left in the account at the end of a payment cycle, not the start – so what is in there before the payments are received, rather than after. Same as your wages. Your savings aren’t what is in the bank on payday, they’re what’s in the bank (or what ISN’T in the bank if you’re me) the day before payday.
Income is income for the period it’s for, and only becomes capital after that period, so even if the payments take your customer over £16k, they will only NQ if they are still over £16k immediately before the next payment is due.
