I guess that's down to your judgement on the person you are working for. Is it the owner? Or a letting agent? If it's the latter then maybe I would or at least arrange to be paid within 28 days. Some people offer 10% of for payment within 7 days.
I personally never get deposits. We did a huge clean a month or so ago, all china, paintings off the walls and cleaned, tapestry taken down for cleaning, it took ages. I never got a deposit and was paid on completion. She was a lovely lady though and the house was 5 mins away from mine so I just didn't ask for a deposit.