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An onboarding checklist for UK new starters

Mellow Editorial·5 min read

Reviewed by Mellow Editorial Team, HR & payroll content team

Getting a new starter fully onboarded in the UK means completing a specific set of legal, payroll and administrative steps before or on their first day — and a few more in the weeks that follow. Miss one and you risk HMRC penalties, employment tribunal exposure, or simply a confused new employee who cannot get paid on time.

Before the start date

Issue a written statement of particulars

Under the Employment Rights Act 1996 (reinforced by updates including the Employment Rights Act 2025), employees are entitled to a written statement of particulars on or before day one. This is not optional. It must cover job title, pay, hours, holiday entitlement, notice periods, and other key terms. For most employers, this takes the form of a contract of employment — which is cleaner and less ambiguous than the bare statutory minimum.

Collect a P45 or ask the employee to complete a starter checklist

If your new starter has a P45 from their previous employer, collect it and enter the details into your payroll software. If they do not have one — perhaps they are starting their first job, were previously self-employed, or simply cannot locate it — they need to complete HMRC's starter checklist. This determines which tax code you apply from day one. Using the wrong code can mean under- or over-deducting income tax, which creates problems for both parties.

Verify the right to work in the UK

You must check that every new employee has the legal right to work in the UK before they start. For British and Irish citizens, this typically means checking a passport. For those with other immigration status, you will check their digital or physical status documents. Keep a dated copy. This is not a formality — employing someone without the right to work carries serious civil and criminal penalties.

Complete any DBS checks if required

If the role involves working with children, vulnerable adults, or in certain regulated sectors, a Disclosure and Barring Service check is mandatory. Allow enough time — enhanced checks in particular can take several weeks.

On or by day one

Set up on payroll

Add the employee to your payroll system with the correct tax code, National Insurance category and pay frequency before you process their first payslip. For most employees you will use NI category A: employer contributions are 13.8% on earnings above the secondary threshold, and employees contribute 8% up to the upper earnings limit, then 2% above it. Employees earning below the personal allowance of £12,570 will pay no income tax, but NI and payroll records still apply from the lower earnings threshold.

Enrol in a qualifying workplace pension if eligible

Auto-enrolment applies from day one of employment if the worker meets the age and earnings criteria. Employer minimum contributions are 3% of qualifying earnings; employee contributions are 5%. You must enrol eligible workers promptly and cannot ask them to wait until a probation period ends.

Provide an itemised payslip

Every employee has the right to an itemised payslip showing gross pay, deductions and net pay. This applies from day one.

Issue the right holiday entitlement information

Full-time employees working five days a week are entitled to 5.6 weeks (28 days) of statutory annual leave, including bank holidays. Make sure your contract and any HR system reflect the correct entitlement and your policy on carrying leave over, booking it, and what happens during the probation period.

Within the first few weeks

Submit an FPS to HMRC

Under Real Time Information (RTI) rules, you must submit a Full Payment Submission to HMRC on or before every payday — including the first one. Late or missing submissions trigger automatic penalties. Make sure your payroll software is set up correctly before that first payroll run.

Register the employee with your liability and employers' liability insurer

Most employers' liability policies require you to notify the insurer when headcount changes. Check your policy terms.

Complete any role-specific compliance training

Health and safety induction is a legal requirement under the Health and Safety at Work Act 1974. Depending on the role, this might also include data protection (GDPR) awareness, manual handling, fire safety or sector-specific certifications.

End-of-year obligations to be aware of from the start

Two deadlines worth noting from the outset: a P60 must be issued to every employee still in employment at 5 April by 31 May each year. If the employee receives any benefits in kind, a P11D (or payrolled benefit equivalent) must be submitted by 6 July following the tax year end.

A note on day-one rights

The Employment Rights Act 2025 has extended and strengthened day-one rights for employees, reducing the scope for employers to use probationary periods as a reason to delay entitlements. Review your contract templates and HR policies to ensure they reflect current law rather than older assumptions about when rights kick in.

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