Can a Second Job Change Your Tax Code? What UK Workers Need to Know

Taking on a second job can be a practical way to increase your income, build experience or manage rising household costs. However, earning money from more than one employer can also affect the way Income Tax is collected through PAYE.

One of the first changes you may notice after starting additional employment is a different tax code appearing on your second payslip. This does not necessarily mean anything has gone wrong. HM Revenue and Customs (HMRC) uses separate tax codes to make sure the correct amount of Income Tax is collected from your combined employment income.

Understanding how tax codes work when you have two jobs can help you identify incorrect deductions, avoid unexpected tax bills and make sure you are not paying more tax than necessary.

Can Having a Second Job Change Your Tax Code?

Yes. Starting a second job can result in HMRC changing or issuing a tax code because your tax position is based on your overall circumstances rather than treating every employment as completely separate.

If you have more than one job, each employment will normally have its own tax code. Your main employment may continue using the standard 1257L code if you are entitled to the full standard Personal Allowance.

Your second employer may instead receive a code such as BR, D0 or D1. The appropriate code depends largely on your expected total taxable income and the tax rates that apply to it.

For the 2026/27 tax year, the standard Personal Allowance remains 12,570. Importantly, this allowance applies per person rather than per job.

Why Does Your Second Job Usually Have a Different Tax Code?

The purpose of having different codes is to prevent the same tax-free allowance from being given twice.

Imagine that your first employer applied your full 12,570 Personal Allowance and your second employer also gave you another 12,570 tax-free allowance. You could potentially receive 25,140 tax-free through PAYE even though you were only entitled to one Personal Allowance.

HMRC therefore normally allocates your Personal Allowance to one employment, often the job paying you the most. Income from another job may then be taxed from the first pound earned.

That does not automatically mean you are paying too much tax. It can simply mean your tax-free allowance is already being used elsewhere.

Which Tax Codes Could Appear on a Second Job?

Several tax codes can be associated with having multiple sources of PAYE income.

The correct code depends on your individual tax circumstances. Scottish and Welsh taxpayers can also see different prefixes and rates.

What Does BR Mean on a Second Job?

BR stands for Basic Rate. When BR is applied, all taxable pay from that particular employment is generally taxed at the basic Income Tax rate of 20%.

For example, suppose your main employment uses your full Personal Allowance and you earn another 5,000 during the year from a second PAYE job.

If BR is appropriate, the second employer would generally deduct basic-rate Income Tax from the entire 5,000 rather than giving you another tax-free allowance.

This arrangement is common where your main job has already used your available Personal Allowance.

Does BR Mean You Are Being Taxed Twice?

No. Seeing BR does not normally mean the same earnings are being taxed twice.

Your employers are simply applying different tax codes to different sources of income. Your main employment may provide your tax-free allowance, while the second job collects tax without an additional allowance.

Problems can occur, however, when HMRC has inaccurate information about your expected earnings or employment status.

Could a Second Job Put You on a Higher Tax Rate?

It can.

Income Tax is ultimately based on your combined taxable income rather than the number of employers you work for.

Someone could remain a basic-rate taxpayer based on their main salary alone but move into a higher tax band once earnings from another job are added.

For example, if your primary employment already places your taxable income close to the higher-rate threshold, additional earnings could cause some income to become taxable at a higher rate.

In these circumstances, HMRC may use a d0 tax code for a secondary source of income. D0 generally means all income from that particular job or pension is taxed at the higher rate of 40% for taxpayers subject to the relevant England, Wales and Northern Ireland rates.

Your actual tax position will depend on your total taxable income and where you are resident for Income Tax purposes.

What Happens to Your Personal Allowance When You Have Two Jobs?

You normally receive only one Personal Allowance for the tax year, regardless of whether you have one job, two jobs or several sources of income.

HMRC commonly allocates the allowance to your main or highest-paying employment.

However, there are situations where the allowance can be divided between jobs.

Suppose you earn 8,000 from one job and 7,000 from another. Neither salary individually exceeds the standard 12,570 Personal Allowance, but together they produce income of 15,000.

If the full allowance remained attached only to the 8,000 job, some of it would be unused there. Depending on your circumstances, HMRC may be able to allocate part of the remaining allowance to the second employment.

This is one reason workers with multiple lower-paying or part-time jobs should check their PAYE records rather than assuming their initial tax codes will always produce the correct result.

What Should You Do When Starting a Second Job?

When you start another job while continuing to work for your existing employer, you will not normally have a P45 from the first job because you have not left it.

Your new employer should instead ask you to complete a starter checklist.

It is important to provide accurate information and indicate that you already have another job where appropriate. The information helps the employer and HMRC determine how PAYE should initially be operated.

Incorrect or incomplete information can sometimes result in a temporary or emergency tax code.

How Soon Can Your Tax Code Change?

HMRC receives payroll information from employers and uses it to maintain your PAYE record. Your new employment details may take some time to appear in your online account.

HMRC states that new employment details should generally be available to view online within six weeks after your first payday.

If HMRC subsequently changes your code, the revised code should appear on a later payslip once your employer receives and applies the instruction.

How Can You Check Whether Your Second-Job Tax Code Is Correct?

Check the tax code shown on each payslip rather than looking only at your main employment.

You can also use your Personal Tax Account or the HMRC app to review your PAYE information. Check that all current employers are listed correctly, old employments have been closed, your estimated income is realistic and your Personal Allowance is allocated appropriately.

Pay particular attention after starting or leaving a job because outdated employment records can sometimes affect PAYE calculations.

What If HMRC Thinks You Still Have an Old Job?

An old employment remaining active on HMRC’s records can create tax-code problems.

For example, HMRC may believe you have three jobs when you actually have only two because a former employer has not been correctly recorded as an employment you have left.

That could affect how your allowances and tax bands are allocated.

You can check your employment information through HMRC’s online PAYE services and update incorrect details, including telling HMRC when you have stopped working for an employer.

Can You Get a Refund If Too Much Tax Is Taken?

Yes. If an incorrect tax code causes excessive deductions, you may be entitled to have the position corrected and potentially receive a refund.

In some cases, correcting the tax code during the tax year allows the adjustment to be made through payroll.

HMRC also reviews PAYE records after the end of the tax year. If you have paid too much or too little, HMRC may issue a P800 tax calculation explaining the difference.

This is why keeping payslips, P45s and other employment records can be useful.

Does National Insurance Work the Same Way as Income Tax?

Not exactly.

Income Tax is based on your overall taxable income, whereas National Insurance contributions generally operate separately for jobs with different employers.

HMRC guidance says that where someone has two or more jobs with different employers, each employer will normally calculate National Insurance based on the earnings it pays.

There are exceptions, including certain situations involving associated employers, so National Insurance should not simply be calculated in the same way as Income Tax.

How Can You Avoid Tax Code Problems With Two Jobs?

The most effective approach is to keep your PAYE information accurate whenever your employment situation changes.

Review your first payslip after starting a second job and compare its tax code with the code used by your main employer. You should also check that HMRC has realistic estimates of how much you expect to earn from each job.

If you stop working for one employer, update your records promptly rather than assuming the change will always be reflected immediately.

Most importantly, remember that having a second job does not automatically mean you are being unfairly taxed. Your tax code is primarily a mechanism used to collect the appropriate amount of Income Tax across your different sources of PAYE income.

Final Thoughts

A second job can change your tax code because HMRC needs to consider income from all your employments when deciding how much tax should be collected.

Your main job may continue using 1257L, while another employment could use BR, D0, D1 or another code depending on your circumstances. Since you normally receive only one Personal Allowance, a second employer cannot automatically give you another full tax-free allowance.

Checking your payslips and HMRC PAYE account after starting or leaving a job can help you catch problems early. If your income estimates, employment records or tax codes appear incorrect, updating HMRC can reduce the risk of paying too much tax or facing an unexpected bill later.