started job before new tax year - bosses classing it as being within new tax year

[livinlavidaloca]

I started my new job on the 4th April and had to fill in the p60 (

I think it was a p46 you filled out, but I don't think it'll make a huge amount of difference,as it's only a couple of days. I assume your boss is paying your paye contributions, so it would mean paying basic rate tax until hmrc alter your tax code at which point a rebate would be due to them, and you'd go on to a normal tax code.

The important thing is not so much when the job started as when you were first paid. So you may have started in 2010/11 but won't be paid until 2011/12.
Haven't you got a P45 to give them?

If you don't tick the box you will get put on a BR rate & pay tax at 20% on the whole amount

Fib & say yes 2 days don't matter

Yes it's the date you are first paid that matters, although it would best if you filled in the form and dated it on the 7th then you wouldn't have to fib.

You may well have overpaid tax in 2010/11 - when did you leave your last job? To reclaim that tax start here.