Originally Posted by stut

Not quite that simple. The 40% only applies to the earnings above £31.8k, with lower tax rates applying to different bands below that. But then you have National Insurance to pay as well. Typically, an estimated or standard rate will be deducted by default before you get the money (although HMRC often get this wrong, so you really need to check it yourself).

I've never seen a salary in the UK quoted after tax - always before. £70k pre-tax would be roughly £48k post tax/NI - but that will depend on any taxable benefits, and whether you need to pay NI if it's a limited term placement.

Oh, and definitely agree re public transport. You may find owning a car is more of a hindrance than a help (I certainly did when I was in London - just parking it is a hassle and expense in itself!)