I don’t know how you are negotiating

but honestly in my opinion your past salary is irrelevant; you should just put “negotiable” on the
application and if they ask — give a range not your specific salary; Most managers have a pay band based on experience and qualifications so that’s what they are looking to balance against. We were told by our corporate HR team that it’s not illegal to ask for a pay
stub but it’s extremely unusual… in this case the winning company bid salaries at 60% the current rate. So if I made $100K I would be offered $60K because it’s a firm fixed price (no room for negotiation). Bottom line, when interviewing I suggest giving a range of perhaps your current salary to $15 more which gives you negotiating room to get to the middle if all goes well.