How does tax work with a 2nd job?

[ASecretLemonadeDrinker]

DH has a day job and today has been offered a 2nd job but how will his tax work? Will it just work itself out (should be simple, I don't think he will hit the higher tax even combined) or will he get 2nd job 'tax free' as yearly it just goes over the tax allowance and then when the p60 happens he gets a tax bill rather than a nice rebate? My mum had a 2nd job and this is what happened, but am not sure if that's an error or just how it works.
THanks

Usually all of your tax allowance applies to the first job, and the second job gets a completely different tax code with no allowance made.

I think you can ring Inland Revenue HMRC whatever they are called and ask.

BUt how does job 2 know about job 1? Does the employer choose the tax code, or is it automatically given once it's 'put through the system'? The employers know he has a full time job, so I presume it's their job to sort a tax code...?

He will have to sign a form for the second employer to say it's his second job and then he will have to pay 20% tax on everything he earns in the second job. If over the tax year he doesn't earn more in both jobs combined than the personal allowance (or only a bit more) then he can claim some tax back - I think that's how it works

I was looking at this the other day. Might be helpful.

Everyone has a tax free personal allowance. Your DH's tax allowance is being used by his first job. When he starts his second job he needs to ask them for form P46 which he completes to say he already has a job.

The new employer will use a basic rate (BR) tax code on his wages from them. At the end of the year when his full income is known he will either have paid the right amount, or he may get some back/ have some to pay.

Depending how much he earns he may also have to pay NI at the second job as well as on his main one.

p46 - ok. I knew he'd have to pay tax on all his 2nd job (his first takes up the 6 odd thousand or whatever first stage) just didn't know how they'd 'know' to do it. Thanks