Pay stubs vs tax records

Pay stubs might be needed if you want to negotiate salary after you receive the offer.

GYM30,
There is no timeline. It all depends on the availability of everybody involved in the approval process. Vacation, biz travels, etc. could delay the process. In my case, it took about 1 month for them to come back with a revised offer. I can't stress this enough: patience is key if you are to go through with this process.

I did not receive any indication of either success or failure. So it was basically a complete silence until I received the revised offer. I learned after the fact that some folks had been traveling for business. So, similar with other steps in the process, you just wait with nothing else to do besides waiting. Really. We all learned through school & work that there is always something you can do to move things along. Not here. Really. (Sorry if I sound a little exasperated -- I've been waiting a long 6 weeks for my visas )

With any negotiation, anything could happen so you should be ready for the worst. Having said that, if you're requesting them to increase base salary to match your current base salary, you will likely get it (based on many similar cases in the forum, including mine).

EDIT:
and of course... a few hours after I wrote the above message, my relo advisor called me to inform that our visas have been approved. What a relief. Thank ! Now we can get back to actually doing the move preparations.