I'm in the UK and I was recently offered a job.
When I went for an interview, they asked for a form of ID and my National Insurance number. I took my passport and a previous payslip with my NI number (I believe I was issued a NI card, but I couldn't find it). I also made photocopies of said documents because they wanted to keep them in their records, but I blacked out information I found unnecessary, such as my salary on the old payslip and a long code on my passport, which included the passport number (in the MRZ). I handed both the original documents and the photocopies to the interviewer, and she kept the photocopies.
It's been several days since I've been given a verbal offer, which I accepted, and today I found out that HR is demanding unredacted copies of the documents to proceed. I asked the hiring manager if things like salary information were something that HR needed, and she said "yes".
I didn't continue to question the situation because kicking up a fuss could easily lead to the offer being withdrawn, and I do need to eat.
A practical way to avoid the salary information is to find my NI card, but I actually see that information as less important, anyway, than passport reference codes etc.
So I'm just wondering: are they really justified in asking for such information (remember, they already have my personal details from my passport, including photo, and my NI number)?
I talked to HR, and there seems to have been some miscommunication between them and the hiring manager, since the only thing they actually wanted from the payslip was the tax code (not salary information). They still wanted the full passport page (for compliance reasons, apparently). Btw, I ended up taking the job.