HMRC will still know where you work on any particular day - assuming you're being paid for the job you're doing on that day.Because it is based on that one day. You could be sacked, made redundant, got a new job the day before and details may not have been updated yet. Say you got a new job and your last day was 20th and you don't start your new job until April for example you would technically be out of work and would put nothing in that question.