We have just completed an application with Santander & they required 3 months' payslips, plus proof of child benefit & tax credits (award statement & bank statement). Of course, you can ask for only your wages to be taken into account, if you so wish, negating the need for the latter.
Depends on the lender. We re-mortgaged last year, when DP had just changed jobs, so a month into a six month probationary period and I wasn't working. Lots wouldn't accept us but the Woolwich (owned by Barclays) did and offered a good deal.
3 months is normal, but if you need to move right away, you could buy using a buy-to-let mortgage (where you don't need to prove income - just that the rent is larger by a certain amount than the mortgage).
Then you could let it to yourself. The early repayments would be larger, but no larger than it'd be to rent a place.
You could then switch to a normal mortgage once you'd got your job sorted out.
DH is moving jobs in 2 months - it isn't with the same organisation, and is temporary for 22 months in the first instance, but will have continuous service as it's all civil service-y and is a similar-ish job.
Our house sale is underway but we don't know if we'll get a mortgage to buy another and right now we can't apply under his new situation as it isn't happening yet, iyswim.
Don't know whether to just rent for 6 months until he's got some wage slips. We can't apply for a mortgage now as in 4 weeks we'd need to inform of the new job and they might then turn round and refuse, and we'd waste tonnes of money on surveys, solicitors etc.
We used nationwide recently and my dh had only just started a new job. They wanted a letter from his employers with his salary, location, job title and the fact it was a permanent role. We use a great ifa who always sorts out life cover, mortgages, pensions etc. he rings around different providers to find us the best fit. It saves so much stress!!!!