Check what a tax code means
Every UK tax code explained, with exact tax-free pay for each pay schedule.
The standard Personal Allowance of £12,570 is given once per person, not once per job, and HMRC usually allocates it to the employment that pays the most [1]. A second job therefore normally runs on a code with no allowance at all, most often BR, which taxes every pound at the 20% basic rate [12].
That single rule explains most of the questions that arrive in payroll inboxes from employees with two jobs: why a small Saturday job loses a fifth of its pay to tax, why a second employer cannot simply use 1257L, and why the figures sometimes need correcting after the tax year ends. It also explains why the second employer is rarely the one who decides the code. HMRC does, from information on the starter checklist and from the employee's record [9].
National Insurance follows a different logic. It is worked out separately for each job, with its own thresholds, unless the employments are with the same employer or with businesses carried on in association [8] [2].
This guide sets out which code a second job gets and why, how BR, D0 and D1 behave on a payslip, when the allowance can be split between jobs, how the Scottish and Welsh versions differ, and what the second employer has to get right. Every worked figure was computed by a payroll engine implementing HMRC's routines for the 2026-27 tax year.
Key takeaways
- The £12,570 Personal Allowance normally sits on the job that pays the most; the second job usually gets BR, D0 or D1 [1] [7].
- BR taxes all pay at 20%, D0 at 40% and D1 at 45%; on £800 a month that means £160, £320 or £360 of income tax.
- A new starter who ticks statement C on the starter checklist is put on BR until HMRC sends a code [9] [11].
- Where neither job uses the full allowance, HMRC can split it between them, for example 800L and 457L [1] [3].
- National Insurance is calculated per job, so a second job paying under £1,048 a month carries no employee NI, though the employer still pays 15% above £417 [4] [15].
- Any mismatch between the codes and the employee's true liability is reconciled after 5 April, usually through a P800 calculation [18].
Why a second job gets a different code
A tax code tells the employer how much tax-free pay to give against the wages it pays. GOV.UK explains that the allowance is "usually split into equal weekly or monthly amounts" across the year [1]. If two employers both applied 1257L, the employee would receive the allowance twice and pay too little tax.
One allowance, allocated to the main job
The Low Incomes Tax Reform Group (LITRG) puts it plainly: HMRC "will generally allocate your personal allowance to your main job", normally the one that pays the most [3]. HMRC's Tax Confident campaign uses the same wording for employees and adds that the most common second-job code is BR [8].
TaxAid warns that where both jobs carry 1257L, the employee "will end up owing" tax once the year is reconciled [6]. The Chartered Institute of Payroll Professionals (CIPP) notes that HMRC "will typically allocate a tax code based on a person's total income from all sources" [7].
What happens when both jobs use 1257L
The cost of a duplicated allowance is easy to show. An employee earns £20,000 a year in a main job and £10,000 in a second job. On 1257L the main job deducts £1,484.20 of income tax. If the second job also runs on 1257L, it deducts £0, because £10,000 sits entirely inside a second, phantom allowance [12] [14].
On the correct BR code, the second job deducts £2,000 instead. That £2,000 is the underpayment HMRC would otherwise have to recover after the year ends, either through a P800 bill or by reducing a future code [18] [25].
The codes HMRC uses for a second job
Three flat-rate codes cover almost every second job in England and Northern Ireland. HMRC's PAYE Manual describes BR as "mainly for secondary sources" and states that the employer "deducts tax at basic rate from all the payments", giving "no allowances" and ignoring higher rates [9].
BR, D0 and D1 compared
GOV.UK's guidance for people with more than one job lists the three codes and the rate each one applies [1]. The table shows what each does to an £800 monthly second-job payslip for a category A employee.
| Code | Rate on all pay | When HMRC uses it | Income tax on £800 a month |
|---|---|---|---|
| BR | 20% basic rate | Total income stays within the basic rate band | £160.00 |
| D0 | 40% higher rate | Main job already uses the allowance and the basic rate band | £320.00 |
| D1 | 45% additional rate | Total income is above the additional rate threshold | £360.00 |
Sources: GOV.UK guidance on more than one job [1], PAYE Manual on codes for special cases [9] and the 2026-27 income tax rates [14].
The PAYE Manual says D0 is used "when tax is due at higher rate and all the allowances are fully given elsewhere" [9]. The D0 tax code guide and the BR tax code guide cover each code in more depth. GOV.UK's employer table confirms that these codes carry no tax-free amount [13].
How BR and D0 compare with the true liability
BR is right for most second jobs, but it can undertax or overtax at the edges. Take an employee earning £48,000 in a main job on 1257L, which deducts £7,084.20 of income tax, and £6,000 in a second job. Taxed together as a single £54,000 income, the liability would be £9,028.40, so the second job's true share is £1,944.20 [14] [23].
| Second job code, £6,000 a year | Income tax deducted | Compared with the £1,944.20 share |
|---|---|---|
| BR | £1,200.00 | £744.20 too little |
| D0 | £2,400.00 | £455.80 too much |
Neither flat-rate code fits exactly, because only part of the second job's pay falls in the 40% band. TaxAid notes that a BR code may undertax once taxable income passes the £37,700 basic rate band [6]. HMRC can correct the gap with a reduced or K code on the main job during the year, or settle it afterwards [25] [18].
Starting a second job: the starter checklist
A new second job rarely comes with a P45, because the employee has not left the first job. GOV.UK confirms that no P45 is issued for a new job while an existing job continues [1]. The new employer instead collects the starter checklist, which HMRC says should be filled in by anyone "working for more than one employer" [10].
How the three statements map to codes
The starter checklist asks the employee to choose one of three statements, and each statement produces a different starting code [11]. Statement C is the one for an employee who has another job or receives a State or workplace pension alongside the new job.
| Statement chosen | Situation | Starting code |
|---|---|---|
| A | First job since 6 April, no other income | Emergency code, cumulative |
| B | Only job now, but another job earlier in the tax year | Emergency code on a week 1 or month 1 basis |
| C | Another job or pension alongside this one | BR |
| None ticked | No statement chosen | 0T on a week 1 or month 1 basis |
Sources: HMRC starter checklist [11], PAYE Manual on codes for special cases [9] and GOV.UK on emergency codes [24].
The PAYE Manual sets out both outcomes for second jobs: BR where the employee has ticked statement C, and 0T for "new employees who have failed to tick" any statement [9]. The CIPP adds that the checklist must "state if a person has another source of income" [7].
Why statement C matters on the first payslip
On an £800 monthly second job, BR and 0T on a month 1 basis give the same income tax of £160, because the whole £800 falls inside one month's basic rate band either way [14] [22]. The difference appears on larger pay, where 0T moves into the 40% band within a single period and BR does not [13].
Ticking statement A or B in a second job by mistake has the opposite effect: the emergency code gives a second allowance and the job undertaxes until HMRC issues a BR code [24]. GOV.UK tells employees to "include that you already have another job" on the checklist for this reason [1]. The 0T tax code guide explains the no-statement route in full.
Splitting the Personal Allowance between jobs
Where the main job pays less than £12,570, part of the allowance goes unused while the second job is taxed in full. HMRC's guidance invites employees to "contact HMRC to check if your Personal Allowance can be split between your jobs" [1]. The Tax Confident campaign describes the same situation: two jobs "that pay less than £12,570 each" [8].
A worked split: £8,000 and £7,000
GOV.UK uses the example of an employee earning £8,000 in one job and £7,000 in another [1]. Giving £8,000 of allowance to the first job leaves £4,570 for the second. In code form that is 800L on the first job and 457L on the second, since the number in a code is the tax-free amount with the last digit removed [12].
| Arrangement | Job 1 (£8,000) tax | Job 2 (£7,000) tax |
|---|---|---|
| 1257L on job 1, BR on job 2 | £0.00 | £1,400.00 |
| Split: 800L on job 1, 457L on job 2 | £0.00 | £484.20 |
Sources: GOV.UK worked example [1], with deductions computed under the PAYE tax table routines [23].
GOV.UK's illustration shows £2,430 of taxable pay and £486 of tax on the second job. The engine gives £484.20 because the PAYE routines treat 457L as £4,579 of free pay, adding 9 to the code number, so taxable pay is £2,421 [23] [22]. The split brings in-year tax close to the £486 the employee actually owes on £15,000 of total income.
When a split is a bad idea
LITRG advises splitting "only" where income from each job "is predictable and stable" [3]. If the second job's hours fall, part of the allowance allocated to it is wasted during the year and the employee waits for a refund after 5 April [18] [28].
Employees can ask for a split, or report a change in expected pay, through the online service or the HMRC app [19] [20]. The employer then receives revised codes for both jobs and applies them from the next payday [21].
Second-job codes in Scotland and Wales
Scottish and Welsh taxpayers carry a prefix on every code, including second-job codes. The prefix changes the rates applied, not the logic of where the allowance sits [16] [17].
The flat-rate codes by jurisdiction
Scotland has more bands than the rest of the UK, so it uses more flat-rate D codes. The Scottish Government publishes the 2026-27 starter, basic, intermediate, higher, advanced and top rates [27]. The table shows each code on an £800 monthly second job.
| Code | Rate on all pay | Income tax on £800 a month |
|---|---|---|
| SBR | 20% Scottish basic rate | £160.00 |
| SD0 | 21% intermediate rate | £168.00 |
| SD1 | 42% higher rate | £336.00 |
| SD2 | 45% advanced rate | £360.00 |
| SD3 | 48% top rate | £384.00 |
| CBR | 20% Welsh basic rate | £160.00 |
| CD0 | 40% Welsh higher rate | £320.00 |
Sources: Scottish income tax rates [27] [16] and Welsh income tax [17].
Why the prefix matters for a second job
A Scottish employee whose second job is coded BR instead of SBR pays the same 20% here, but a D0 in place of SD0 would apply 40% rather than 21%, a gap of £152 on £800 a month. The prefix follows the employee's main home, not the employer's address, so a second employer in England can receive an S code [16] [12].
National Insurance and pensions in a second job
Income tax looks at total income across jobs. National Insurance, in most cases, does not. The National Insurance Manual states that where someone works for different employers at the same time, "contributions for each employment are normally calculated separately" [4].
Thresholds apply job by job
Each job therefore has its own primary threshold of £1,048 a month for the employee and secondary threshold of £417 a month for the employer [15] [32]. The table shows two second-job payslips for a category A employee.
| Second job, BR code | Income tax | Employee NI | Employer NI |
|---|---|---|---|
| £800 a month | £160.00 | £0.00 | £57.45 |
| £1,500 a month | £300.00 | £36.16 | £162.45 |
Sources: National Insurance rates and thresholds [15] and the HMRC Tax Confident page on multiple jobs [8].
An employee with two jobs each paying £800 a month pays no employee National Insurance on either, even though £1,600 a month in a single job would cross the primary threshold and carry £44.16 of employee NI [8] [3]. The guide to employer National Insurance covers the 15% rate in detail.
When earnings must be aggregated
The separate-calculation rule has exceptions. All earnings from employments "with the same employer must be aggregated" before NI is worked out, and earnings from different employers must also be added together in prescribed circumstances [5]. The main case in practice is employers who "carry out business in association" [2].
Where aggregation applies, GOV.UK tells the employer to add the earnings together, calculate NI on the combined figure, set the "Aggregated earnings indicator" to "Yes" on the Full Payment Submission, and record "0.00" in the year-to-date NI fields of the other job [2]. The legal basis sits in regulation 15 of the Social Security (Contributions) Regulations 2001 [4].
Auto-enrolment is assessed per job
Workplace pension duties also look at each employment separately. LITRG notes that the lower level of qualifying earnings is disregarded "in each employment" [3], so a second job paying below the £10,000 earnings trigger does not create an automatic enrolment duty even when combined pay is higher [26].
What the second employer must get right
The second employer's position is simple to state: it operates the code HMRC gives it and reports each payday. GOV.UK's employer guidance says "the way you work out their PAYE tax won't change" because an employee has another job [2].
Operating the code HMRC sends
When HMRC issues a P6 or P9 code for a second job, the employer applies it from the next payday and uses any previous pay and tax figures supplied with it [21]. Codes and notices arrive through PAYE Online or the payroll software's data service [31].
The employer does not move the allowance between jobs on an employee's request, and it does not replace a BR code with 1257L because the employee says the other job has ended. GOV.UK states that employers should only change a code when HMRC tells them to [21] [13]. Employers running HMRC-recognised payroll software for SMEs see a new code applied as soon as the notice is downloaded.
Reporting through RTI
Each payday the employer sends a Full Payment Submission on or before the date of payment, showing the code operated, pay and deductions [29]. HMRC uses the submissions from both employers to spot when two jobs are both receiving an allowance and to issue a corrected code [30] [25].
Bureaux that handle both of an employee's employers for different clients still run the two payrolls separately, unless the clients are associated for NI purposes. A multi-client payroll dashboard that flags employees on BR, D0 or 0T makes it easier to check that each code still matches the latest notice [21].
Platforms that embed payroll
Platforms that run pay calculations through the HMRC-recognised payroll API pass the tax code as a field, prefix included, on every request; the code formats accepted are listed in the API documentation. The engine then applies BR, D0, D1 and the Scottish and Welsh variants exactly as HMRC's tax table routines describe [23]. The results flow into the same Full Payment Submission that any recognised product sends on or before payday [29].
After the tax year ends
The codes used during the year are an estimate. After 5 April HMRC compares the tax deducted in both jobs with the liability on total income and sends a P800 calculation if the two differ [18] [1].
An overpayment, typical where D0 overshoots or where a split allowance went unused, is repaid to the employee [28]. An underpayment, typical where BR undershoots for a higher-rate taxpayer, is usually collected by reducing the following year's code, which the employer sees as a new code rather than a separate deduction [18] [34].
Check a second-job code before the next payrun
Before entering a code from a notice, an employer can confirm what BR, D0, an S or C prefix or a split code such as 457L means with the Moonworkers tax code checker, which decodes standard, flat-rate, K and emergency codes.
On your payslip, P45 or P60. Suffixes W1, M1 or X welcome.
What you'll get
Enter any UK tax code to see:
- · what each letter and number means
- · which nation's rates apply (S and C prefixes)
- · cumulative vs emergency W1/M1/X basis
- · the exact tax-free pay for every pay schedule, to the penny
Try 1257L, a K code, or an emergency W1 code.
Payroll that applies every tax code correctly
Moonworkers runs the full HMRC exact percentage method on every payslip, including K codes, emergency codes and in-year code changes, and files RTI automatically.
Conclusion
A second job is taxed as a slice of the employee's total income, not as an income in its own right. That is why the allowance stays with the main job, why the second job's code is usually a flat rate, and why the flat rate is only ever an approximation of the true liability. BR, D0, D1 and their Scottish and Welsh counterparts are HMRC's way of getting close during the year, with the P800 reconciliation closing whatever gap remains.
For employers the work is narrower than it looks: operate the code HMRC sends, collect an accurate starter checklist, calculate National Insurance on the job alone unless the employments are associated, and report each payday. As more people combine employments through platforms, agencies and gig work, the accuracy of second-job taxation depends increasingly on how quickly codes move from HMRC to every payroll an employee touches, and on systems that apply them without manual re-keying.
Frequently asked questions
Why is 20% tax taken from all the pay in a second job?
The second job is usually on code BR, which gives no tax-free allowance because the full £12,570 is already used by the main job [1]. Every pound is taxed at the basic rate of 20% [12]. If the main job pays less than the allowance, the employee can ask HMRC to split it between the two jobs.
Can an employee choose which job gets the Personal Allowance?
The employee cannot instruct the employer directly, but can ask HMRC to move or split the allowance [19]. HMRC normally gives it to the job that pays the most [3]. HMRC then sends new codes to both employers, who apply them from the next payday.
Does a second job affect National Insurance?
Usually not. National Insurance is worked out separately for each job with different employers, each with its own thresholds [4]. Earnings are added together only when the jobs are with the same employer or with employers carrying on business in association [2].
What happens if both jobs use the 1257L code?
The employee receives the allowance twice during the year and pays too little tax. HMRC usually spots the duplication from the payroll submissions and issues a BR or similar code to one job [25]. Any shortfall left at the end of the year appears on a P800 calculation and is normally collected through a later tax code [18].
