Employer PAYE Reference Numbers Explained: UK Payslip Codes 2026/27

Your UK payslip is full of reference numbers - Employer PAYE Reference, Office Number, Accounts Office Reference, Employee Number, NI Number, Works Number, Tax Code. Knowing what each one identifies (and which ones HMRC needs when you raise an issue) is essential for any payroll question. This guide decodes them all.

At-a-glance: every reference number on a typical UK payslip

Reference	Format	What it identifies	Who issued it
Employer PAYE Reference	3 digits / letters and numbers (e.g. 120/AB12345)	Your employer's tax office + their PAYE scheme	HMRC
Office Number	3 digits (the part before the /)	The HMRC office handling your employer's payroll	HMRC
Accounts Office Reference	13 characters (e.g. 120PA00123456X)	Where employer pays PAYE/NI/student loan to HMRC	HMRC
Employee Number / Works Number	Variable (often 4-8 digits)	YOU, in your employer's payroll system	Your employer
National Insurance Number	9 characters (e.g. AB123456C)	YOU, in HMRC's records	HMRC
Tax Code	4-6 chars (e.g. 1257L)	Your tax-free allowance level	HMRC
NI Category Letter	1 letter (e.g. A)	Your NI band class	HMRC
Pay Reference Period	Date range	The period this payslip covers	Your employer

Employer PAYE Reference (the most-needed one)

The Employer PAYE Reference is the single most-frequently-needed identifier when you raise issues with HMRC about your tax or NI.

Format

A 3-character HMRC office number, followed by /, followed by an alphanumeric employer reference. For example:

120/AB12345

• 120 = the HMRC tax office number
• AB12345 = your employer's specific reference within that office's records

Where you find it

• Top of every payslip (legally required since the Employment Rights Act).
• Top of your P60 (annual summary).
• Top of your P45 (when you leave).
• In your Personal Tax Account under "PAYE Income Tax History" → click your employer.

When you need it

• Calling HMRC about a tax-code issue: HMRC asks for your NI number AND the Employer PAYE Reference.
• Filing a Self Assessment that includes employment income: the SA100 supplement requires the reference.
• Disputing a P11D valuation: HMRC asks for it.
• Mortgage application: lenders verify your employment by cross-referencing the PAYE record with your employer's name + reference.

Office Number

The first 3 digits of the Employer PAYE Reference (the part before the /). Identifies which HMRC office handles your employer's PAYE scheme.

You don't usually need this on its own - it's part of the full Employer PAYE Reference. But if your employer is investigating PAYE issues internally, the payroll team uses the Office Number to direct queries to the right HMRC team.

Accounts Office Reference

A separate 13-character reference, distinct from the PAYE Reference. Used by your employer when paying PAYE/NI/student loan deductions to HMRC.

Format example:

120PA00123456X

You'll see this on:

• Your employer's PAYE accounting documentation (you don't usually see it).
• Your P60 (occasionally).

You don't need this for personal HMRC queries - it's an employer-side identifier.

Employee Number / Works Number

Your employer's internal identifier for you. Format varies by employer:

• 4-8 digits is common (e.g. 045892).
• Some employers use letter prefixes (e.g. EMP-12345 or STAFF-001).
• Some use your full name + a sequence.

This number identifies you in:

• Your employer's payroll system.
• Time-and-attendance systems.
• HR records.
• Pension scheme records.

You'd quote this when:

• Contacting your own payroll team.
• Filing an internal grievance.
• Asking for a duplicate payslip or P60.

National Insurance Number

A 9-character HMRC identifier in the format AA NN NN NN A (two letters, six digits, one letter, often shown without spaces).

This is YOUR identifier in HMRC's tax-and-benefit system. It's used for:

• Income Tax + NI records.
• State Pension entitlement.
• Benefits + Universal Credit.
• Student loan accounts.
• Employer right-to-work checks.

You should NEVER share your NI number except with:

• Your employer (legitimate use).
• HMRC and DWP (legitimate use).
• Your bank or building society for ISA/pension contributions.
• A regulated financial adviser or accountant you've engaged.

Tax Code

A 3-6 character code combining digits + letter(s) showing your tax-free allowance level for the period.

Common formats:

• 1257L - standard 2026/27 cumulative code with full Personal Allowance (£12,570).
• 1257L W1 / M1 / X - same allowance but non-cumulative this period.
• BR - Basic Rate (no PA, all 20%).
• 0T - No allowance, banded rates 20/40/45.
• K473 - Negative allowance code (BIK exceeds PA - see our K-code guide).
• D0 - All income at 40% (higher rate).
• D1 - All income at 45% (additional rate).
• NT - No tax (rare; usually overseas-resident special cases).

See our tax codes guide for the full list.

NI Category Letter

A single letter on your payslip showing which NI band class applies to you. Common categories for 2026/27:

Letter	Who it applies to
A	Standard adult employees
C	State Pensioners (no employee NI but employer still pays)
F	Apprentices under 25
H	Apprentices under 25 (Investment Zone variant)
J	Deferred NI (people with multiple jobs above UEL)
L	Investment Zone workers
M	Under 21 (employer NI rate reduced)
N	Investment Zone Under 21
V	Veterans (employer NI rate reduced for first 12 months of civilian employment)
X	NI exempt (specific circumstances)
Z	Under 21 deferred

The wrong category letter can result in over-deduction or under-deduction of NI - common when your circumstances change (you turn 21, become a state pensioner, complete an apprenticeship). See our NI category letters guide.

Pay Reference Period

The dates the payslip covers. For monthly-paid workers, typically:

• "1 May 2026 to 31 May 2026" or
• "Pay Period 02" (May, where Period 01 = April).

For weekly-paid workers, "Week 5" or similar.

This matters because:

• Tax codes apply per pay period - a code change affects the period it's introduced.
• Statutory pay (SSP, SMP, SPP) calculation depends on the pay reference period.
• Disputes about overtime or back-pay reference specific periods.

Other reference numbers you might see

Depending on your employer / sector:

• Pension Scheme Reference: 8-10 digits, your pension provider's record for you.
• CIS Verification Number: 6 digits, for construction industry subcontractors.
• Job Reference / Position Code: internal employer code identifying your role.
• Cost Centre: internal accounting code for which department's budget pays you.
• Department Code: which team or division you sit in.

These are employer-internal references - useful for internal queries but not relevant to HMRC.

What to do if a reference is wrong

If the Employer PAYE Reference on your payslip differs from what HMRC has for that employer:

1. Sign in to your Personal Tax Account at gov.uk/personal-tax-account.
2. Click PAYE Income Tax History → your employer.
3. Compare the reference shown with what's on your payslip.
4. If different, contact your employer's payroll. HMRC's record is the authoritative one.
5. If your NI Number is wrong on your payslip, this is a serious error - your NI contributions may not be credited to you. Email payroll immediately AND contact HMRC on 0300 200 3500 (NI helpline).

A complete payslip read-through

A well-structured UK payslip top-section looks like:

─────────────────────────────────────────────
ACME Limited                  PAYSLIP
123 High Street               
London, EC1V 2NX              

Employee:        John Smith
Employee No:     045892
NI Number:       AB123456C
Tax Code:        1257L
NI Category:     A
Pay Period:      May 2026 (Period 02)
Pay Date:        31 May 2026
Employer PAYE:   120/AB12345
─────────────────────────────────────────────

Every field above carries a specific function. Confusing them is the #1 source of payroll-query confusion.

Disclaimer

PayslipIQ provides automated educational guidance based on the figures you supply. It is not regulated payroll or tax advice. Reference numbers are factual identifiers, not regulated tax matters; for substantial PAYE issues, contact HMRC on 0300 200 3300 (PAYE helpline) or use a CTA-qualified tax adviser.