Payroll questions tend to surface at inconvenient moments. A payslip looks wrong, a lender asks for proof of income, or HMRC correspondence needs clarifying. In many of these situations, people are asked for a payroll number and realise they are not entirely sure what it is or where to find it. This uncertainty is common, even among long-term employees.
The confusion usually stems from the assumption that a payroll number works like a National Insurance number or another official identifier. In reality, it serves a different, more limited purpose. Knowing how payroll numbers are used in the UK, how they are assigned, and where they appear in everyday documents can remove much of the friction from dealing with employers, payroll teams, and third parties.
The explanations below reflect standard UK payroll practices, HMRC guidance, and how payroll operates in real workplaces. The aim is to provide clear, dependable guidance grounded in how payroll actually functions, rather than abstract definitions.
What a Payroll Number Is
Definition and purpose
A payroll number is an internal reference number assigned by an employer to identify an employee within their payroll system. It allows the employer to process pay accurately, apply the correct tax and National Insurance deductions, manage benefits, and maintain consistent employment records. It is not issued by the government and does not follow a nationally prescribed format.
In the UK, payroll numbers are commonly used alongside PAYE systems, pension administration, and payroll reporting. HMRC permits employers to include payroll numbers in submissions, but they are optional and mainly serve internal tracking purposes.
Payroll number vs statutory identifiers
A common misunderstanding is to treat payroll numbers as equivalent to legally defined identifiers. Each serves a distinct role.
- A National Insurance (NI) number is issued by the UK government and remains with an individual for life.
- A PAYE reference identifies an employer or payroll scheme registered with HMRC.
- A payroll number identifies an employee within a single organisation’s payroll system.
When an individual changes employers, their payroll number will almost always change as well.
Why payroll numbers exist
Payroll systems handle sensitive financial and personal data at scale. Even in small organisations, relying solely on names can lead to errors, particularly where employees share similar names or change their surname. Payroll numbers provide a stable internal reference that links pay, deductions, pensions, and year-end records without ambiguity.
How Payroll Numbers Work in Practice
Assignment by the employer
In the UK, payroll numbers are created and assigned by employers or their outsourced payroll providers. There is no legal requirement governing their structure. Some employers use simple sequential numbers, while others adopt alphanumeric formats linked to departments, locations, or cost centres.
Examples include:
- Sequential numbers such as 00123 or 00456;
- Alphanumeric codes such as LDN-EMP-4589.
Once assigned, the payroll number usually remains unchanged throughout employment. In some cases, particularly where an employee leaves and later returns, a new number may be issued.
Use in payroll processing
Payroll numbers are used internally for tasks such as:
- Running weekly or monthly payroll;
- Calculating tax and National Insurance contributions;
- Administering workplace pensions under auto-enrolment;
- Producing payslips and P60s;
- Managing statutory payments, including Statutory Sick Pay (SSP) and Statutory Maternity Pay (SMP).
Although payroll numbers can be included in Real Time Information (RTI) submissions, HMRC relies primarily on National Insurance numbers and personal details to identify individuals.
Relationship with HMRC
From HMRC’s perspective, payroll numbers are supplementary. Employers are permitted to leave the payroll number field blank in RTI submissions if one is not used. This reinforces that payroll numbers are an administrative tool rather than a statutory requirement.
Common Situations Where a Payroll Number Is Needed
People typically look for their payroll number when a specific issue arises rather than as part of routine administration. Common scenarios include:
- Querying an error or discrepancy on a payslip;
- Completing internal HR or finance documentation;
- Communicating with an employer about tax or pay adjustments;
- Providing proof of income for a mortgage or rental application;
- Reconciling records after changing roles within the same organisation;
- Reviewing pension contributions or salary sacrifice arrangements.
In these cases, the payroll number helps organisations match records efficiently. It does not, by itself, carry legal or tax authority.
Where to Find a Payroll Number
In most cases, the payroll number already appears in documents or systems accessible to the employee. The difficulty is often recognising it or knowing how it is labelled.
Payslips
Payslips are the most reliable source. UK payslips usually display the payroll number near the employee’s name or tax details. Common labels include:
- Payroll No;
- Employee No;
- Staff ID;
- Emp Ref.
Digital payslips accessed through employee portals often contain the same information, though it may be located within a detailed view rather than the main summary.
P60 forms
A P60 provides a summary of pay and deductions for the tax year. Many employers include the payroll number on this document, particularly those using structured payroll software, though it is not guaranteed.
Employment contracts and offer letters
Some employers, especially in larger organisations or the public sector, include payroll or employee reference numbers in employment paperwork. This is less common in smaller businesses.
HR or payroll portals
Employee self-service systems often display payroll or employee numbers under personal or employment details. Access usually requires login credentials provided by the employer.
Contacting payroll or HR
If documents are unavailable or unclear, contacting the payroll or HR team is the most direct solution. After confirming identity, they can confirm the correct payroll number and clarify whether more than one exists.
Key Sources and What to Expect
| Source | How Reliable | Typical Label Used | Notes |
|---|---|---|---|
| Payslip (paper or digital) | High | Payroll No / Employee No | Fastest and most common source |
| P60 | Medium–High | Payroll Number | Often included, but not guaranteed |
| HR portal | High | Employee ID / Payroll ID | Requires active access |
| Employment contract | Medium | Employee Reference | May not be present |
| HR or payroll team | Very High | Official payroll number | Identity checks may apply |
Reviewing these sources resolves most payroll number queries. Where no payroll number can be found, it often reflects an employer’s decision not to use them consistently rather than an administrative error.
Common Problems and Warning Signs
Confusing payroll numbers with NI numbers
Using a National Insurance number in place of a payroll number is a frequent mistake. While NI numbers identify individuals for tax purposes, they do not replace internal payroll references and can cause mismatches in employer systems.
Treating payroll numbers as universal
A payroll number has meaning only within the organisation that issued it. Providing an old payroll number to a new employer or lender is rarely useful and may delay processing.
Multiple payroll numbers with one employer
An individual may legitimately have more than one payroll number if they have:
- Changed roles or departments;
- Moved between different PAYE schemes within the same organisation;
- Returned after a break in employment.
In these cases, payroll should confirm which number applies to current records.
Missing payroll numbers on documents
The absence of a payroll number on payslips or P60s does not necessarily indicate a problem. Some employers choose not to display them or do not use them at all.
Who Is Affected by Payroll Numbers
Employees
Employees most often encounter payroll numbers when resolving pay or tax issues. This includes:
- New starters learning to interpret payslips;
- Long-term employees reviewing deductions;
- Contractors paid through PAYE;
- Workers returning from parental or long-term sick leave.
Employers and payroll administrators
For employers, payroll numbers support efficient administration, particularly in larger workforces. Consistent use reduces duplicate records and reporting errors.
Accountants and advisers
Accountants and tax advisers may request payroll numbers when reconciling employer records, though HMRC interactions primarily rely on statutory identifiers.
Lenders and third parties
Lenders, letting agents, or auditors sometimes request payroll numbers as part of income verification. In practice, providing payslips that clearly show the number usually satisfies these requests.
Practical Recommendations for Finding and Using a Payroll Number
- Check the most recent payslip before contacting HR or payroll.
- Keep key employment documents, such as P60s and contracts, stored securely.
- Use payroll numbers only in employer-related contexts.
- Avoid guessing or substituting another identifier if the number is unknown.
- Expect payroll numbers to change when moving between employers.
- Share payroll numbers only when necessary, as they form part of internal employment records.
Clear labelling and consistent use by employers significantly reduce confusion and unnecessary queries.
Legal and Regulatory Context in the UK
UK payroll operations are shaped by HMRC requirements, employment law, and data protection legislation. Payroll numbers themselves are not defined by statute, but their use falls under broader obligations relating to accurate record-keeping and personal data protection.
Employers are expected to:
- Maintain secure payroll records;
- Ensure employee data is accurate and current;
- Limit exposure of internal identifiers such as payroll numbers.
Employees have the right to access personal data held about them, including payroll numbers, under UK data protection laws.
A payroll number is best understood as a practical internal reference rather than an official personal identifier. Within the UK system, it supports day-to-day payroll administration but does not replace statutory details such as a National Insurance number. For most employees, it is already visible on payslips, P60s, or HR systems, and when it is not, payroll or HR can confirm it quickly.
Recognising the limited role of payroll numbers helps prevent common errors, such as using outdated references or confusing them with government-issued identifiers. With a clear understanding of how and where payroll numbers are used, dealing with pay-related queries becomes more straightforward and far less disruptive.