Working a second job

One job might be the ideal position to be in, but sometimes life has another plan. If you end up working two jobs then you’re probably gonna be exhausted by the time your head hits the pillow. To help you out The Mix has found out all the answers to your second job queries.

A young woman is walking back home from her second job. This is a full-body image.

Is it legal to work two jobs?

Legally, there’s nothing stopping you from having extra jobs, but you’ll need to think about:

  • How many hours you can work, legally speaking
  • Paying tax for two jobs
  • What your contract says

How many hours can I work in total?

By law, your employer can only ask you to work 48 hours a week. Technically speaking you’re allowed to work more hours (over two jobs). The catch is that your main employer needs to know that you’re working above these hours elsewhere. If you’re still a bit confused then take a look at our article on working hours and breaks here for more info.

“If you’re working over 48 hours because of a second job then your main employer needs to have a signed opt-out agreement from you and should monitor the hours you work in a week,” says Sue Terry from the Advisory, Conciliation and Arbitration Service (Acas). “ This is so that they’ll know when to have a chat with you in case they feel like your second job is starting to affect your performance at this one.” 

If you’re under 18, the law is slightly different. You can’t work more than eight hours a day, and no more than 40 hours a week. So you basically can’t get a second job. And before you start scheming, there’s no way around this. We checked.

Now onto the question that you’ve probably been waiting for (or maybe even skipped this part for) How much tax do you pay on a second job? 

Is there a second job tax?

There’s no such thing as second job tax in those specific words, but you shouldn’t start opening Amazon just yet. You’ll still pay tax and national insurance on your second job; same as any job.

Although it’s worth keeping in mind that things can get a little complicated. This is because your personal allowance (the amount you can earn without paying tax) is unlikely to be taken into account when calculating your second job tax code. By default, all of your other earnings beyond your first job will be taxed at at least the basic rate. So if your total income puts you into a higher rate tax band you’ll pay a higher rate of tax on earnings over the band threshold.

To remedy this, you can always ask HMRC for your personal allowance to be split between your two jobs next tax year (if its already ended). And if you end up overpaying you can claim any overpaid tax back which can change the answer to How much tax do you pay on a second job? pretty significantly. While you’re at it you can also ask about different forms of tax relief. But if you don’t feel like talking to someone else right now, you can always learn more about income tax here.

Tax calculations might also get a little more complicated when you reach state pension age. Don’t worry though, you’ve got plenty time working job(s) before that becomes an issue.

How to get a P46, or Starter Checklist

You won’t have a P45 (tax form transferring tax and payroll details from old employer to new employer) when you start your second job. Previously you needed to get a P46 (tax form that replaces P45 if you don’t have one), however these have now been replaced with what’s known as a ‘Starter Checklist’. These checklists can be filled in online and are used by your new employer to add you to their payroll.

This way your employers will be aware you have another job, but you don’t have to tell them where you’re working or how much you’re earning. Plus, you’ll have two jobs tax codes – one for each (and if you have three jobs, you’ll have three codes).

Two jobs tax and National insurance

You’ll also have to make National Insurance contributions on both jobs if you’re paid over a certain amount. If both of your jobs are low paying, however, you may not have to pay NI at all since you have a second job tax code. Although you’ll have to work out which pay class you’re in for each job as well. 

You can learn more about national insurance contributions here.

It’s important to check that the right tax code is being used for each job. So have a look at your payslips. If you have multiple tax codes, or you think you’re paying too much tax, it’s worth contacting HMRC.  That way you can make sure you’re paying the right amount of tax as well. You can also learn more about PAYE tax codes here.

Can my contract stop me from having a second job?

An employer won’t normally mind if you have a second job, but that’s not a guarantee. You should always check your current contract before applying anywhere else. For example, it could limit the jobs you can take if it says something about your behaviour outside work not affecting your company’s reputation, or causing a conflict of interest.

Honesty is the best policy which is why it’s worth being open with your employer about your other job from the beginning. That way they can support you when you need it. Not to mention, legally speaking they can’t stop you from taking a second job if there’s nothing in your contract that’s against it and there aren’t any obvious problems with your performance. So you have nothing to worry about. If they try to, you should get specialist advice from Acas or your local Citizens Advice Bureau (CAB).

We should mention that any work that involves creating or inventing – whether that’s graphic design, journalism or writing computer programs – usually has a clause in your contract that states your employer owns all your creations of that type; even if you come up with them when you’re not at work. Some employers may be OK with you doing the same kind of work for other companies. Regardless, it’s best to get this in writing. Otherwise you might end up reenacting The Social Network trying to find out who owns what.

  • Acas offers free advice about everything to do with employment law. Call them on 0300 123 1100.
  • Share your experience of working a second job on our discussion boards.

Next Steps

  • Acas offers free advice about everything to do with employment law. 0300 123 1100
  • Chat about this subject on our Discussion Boards.
  • Need help but confused where to go locally? Download our StepFinder iPhone app to find local support services quickly.

By Nishika Melwani

Updated on 20-Mar-2022