UK What Is PAYE

PAYE looks straightforward: deduct tax from wages, send it to HMRC.

But if you are setting up payroll for the first time or bringing it in-house, the compliance reality is more demanding than most business owners expect.

The real question is not what PAYE is, but whether you can handle the operational burden without creating penalty risk or cashflow problems. The answer determines whether you run payroll internally or outsource it.

What is PAYE?

Pay As You Earn (PAYE) is the system UK employers use to collect income tax and National Insurance contributions directly from employee wages before paying them.

In our assessment of first-time employers, the on-or-before RTI submission rule is understood in principle but missed in practice when payroll runs on the same day as payment.

When you pay an employee, you calculate what they owe in income tax and National Insurance, deduct it from their gross pay, and send it to HMRC. The employee receives their net pay.

You are responsible for the accuracy and timing of every submission.

PAYE applies to any business paying employees above the Lower Earnings Limit (£125 per week for 2025-26). If you pay anyone more than £1,048 per month, you need PAYE registration.

This is not voluntary. Once you cross the threshold, PAYE becomes a legal obligation with criminal liability for deliberate avoidance, as HMRC sets out in its guidance on PAYE and payroll for employers.

The moment you hire that first employee over the threshold, the HMRC clock starts ticking.

How does PAYE work in practice?

PAYE operates through Real Time Information (RTI) submissions to HMRC. Every time you pay employees, you must send payroll data to HMRC on or before the payment date.

We find the monthly payment-to-HMRC deadline on the 22nd creates the most cashflow stress for growing businesses, especially those that lean on PAYE holding funds as short-term working capital.

The process creates three ongoing obligations that many business owners underestimate:

Monthly payment to HMRC

By the 22nd of each month, you must pay HMRC everything you have deducted from employees, plus employer National Insurance contributions.

For a team of 10 earning £35,000 each, this means sending HMRC approximately £10,500 every month.

Miss the payment by a single day? That is £525 in penalties straight away.

The cashflow trap catches businesses in their second year. They spend the money sitting between payroll and HMRC payment on supplier invoices, then the 22nd arrives and the HMRC payment bounces.

RTI submissions for every payroll run

Before paying employees, you submit Full Payment Submission (FPS) data to HMRC. This includes gross pay, deductions, and National Insurance for every employee.

HMRC processes 54 million FPS submissions annually. The most common rejection reasons are incorrect National Insurance numbers, wrong tax codes, and timing errors.

Each rejected submission delays your payroll and creates work to resolve.

Friday afternoon, payroll due, and HMRC rejects your submission because someone’s NI number has a typo. Your weekend just got complicated.

Year-end reporting

By 19 May each year, you must submit final returns and provide P60s to all employees. Late submission triggers automatic penalties starting at £100 per 50 employees, scaling to £400 per month for larger employers.

Your accountant cannot submit these for you unless they have formal payroll agent status with HMRC. If you handle payroll internally, year-end compliance is your responsibility.

The May deadline arrives whether your business is thriving or struggling. HMRC does not negotiate.

Why does PAYE matter for your business?

PAYE affects your business in three ways that extend beyond simple tax collection:

In our review of HMRC enforcement data, late-payment penalties accumulate faster than employers expect: a three-month streak can produce combined penalties exceeding the monthly cost of outsourcing.

Cashflow management

PAYE creates a monthly cashflow commitment to HMRC that you cannot delay or negotiate. For a business with £30,000 monthly payroll, you typically remit £8,000-10,000 to HMRC by the 22nd.

Picture this: it is the 20th, your biggest client payment is late, and £10,000 is due to HMRC in two days. Your options are overdraft fees or HMRC penalties. Neither feels like a choice.

Smart businesses create a separate PAYE holding account. They transfer deducted funds immediately after payroll. It removes the temptation when supplier invoices pile up.

Administrative burden

PAYE requires consistent monthly admin. Each payroll run triggers RTI submissions, employee record updates, and payment reconciliation with your bank.

When employees join, leave, or change circumstances (new tax code, student loan status, pension opt-out), you update HMRC records immediately.

Holiday pay, SSP administration, and benefit-in-kind reporting all flow through PAYE.

The burden compounds. New starter on Monday means P45 processing. Tax code change arrives Tuesday.

Someone switches pension provider Wednesday.

By Friday you are troubleshooting rejected RTI submissions instead of growing your business.

Penalty and compliance risk

PAYE penalties compound quickly. A late RTI submission costs £100 for up to 50 employees. Submit late for three consecutive months and HMRC imposes additional 5% charges on your total tax liability.

Persistent non-compliance triggers compliance checks. HMRC audits your records, interviews directors, and can pursue criminal prosecution for deliberate tax evasion.

Your bank manager notices HMRC enforcement action. Your overdraft facility gets reviewed. The domino effect of PAYE problems extends far beyond the original penalty.

What are the alternatives to running PAYE yourself?

You have three options for PAYE compliance, each with different cost and control trade-offs:

In-house payroll software

Software like Sage, Xero Payroll, or BrightPay handles calculations and RTI submissions. You maintain control over timing and employee data, but remain responsible for compliance and accuracy.

The software vendors promise “simple, automated payroll”. What they do not mention: you still need to understand tax codes, process starters correctly, and handle HMRC queries when submissions fail.

Choose this if you have reliable admin capacity and genuinely enjoy detail work. The software costs £10-30 monthly.

Your time runs 4-8 hours monthly for a 10-person team, more during rate changes and year-end.

Bureau payroll service

A payroll bureau handles all calculations, submissions, and compliance for a fixed monthly fee. You provide timesheet data, they process payroll and remit funds to HMRC.

This removes penalty risk and ensures expertise, but creates dependency on the bureau’s timing and processes. If they make errors, you remain legally responsible as the employer.

Bureau pricing typically ranges from £15-25 per employee per month.

The relief when someone else handles year-end reporting is worth considering. No May panic about P60s.

Accountant-managed payroll

Your accountant processes payroll as part of broader financial services. This integrates payroll with your accounting records and tax planning, but limits payroll timing flexibility.

Most accountants process payroll on fixed monthly cycles. Need to pay a new starter mid-month? Too bad.

Wait for next month’s run or find another solution.

The integration advantage is real. Your accountant sees the full picture: payroll costs, corporation tax, dividend planning. For businesses prioritising tax efficiency over payroll flexibility, this works.

The smartest decision depends on your growth stage. Start-ups often use accountant payroll until complexity demands more control. Scale-ups bring it in-house or use bureaus for flexibility.

PAYE FAQs

How quickly do I need to register for PAYE?

You must register for PAYE before your first payday if any employee earns above the Lower Earnings Limit for National Insurance contributions. HMRC needs 2-4 weeks to process new registrations, so apply immediately after hiring your first employee. Operating payroll without PAYE registration is automatic non-compliance and triggers backdated penalties on every unreported wage payment.

What happens if I miss an RTI submission deadline?

HMRC imposes automatic penalties for late RTI submissions, starting at £100 for up to 50 employees on the first slip in a tax year. Subsequent late submissions in the same year scale to £200, then £300, then £400. These are per-submission penalties, not annual charges, so multiple slips compound fast.

Can I use my accountant to handle PAYE submissions?

Your accountant can handle PAYE only if they register as your payroll agent with HMRC, because without agent status they cannot submit RTI data on your behalf. Ask your accountant to confirm their HMRC agent registration before delegating PAYE responsibilities. You remain legally responsible for compliance even with agent representation, so retain copies of every submission.

Do I need PAYE for contractors and freelancers?

PAYE applies to employees only, so genuine contractors invoice you as self-employed individuals and handle their own tax obligations. However, IR35 rules may require you to apply PAYE to contractors who work like employees. Check the employment status tests before classifying workers as contractors, because HMRC reclassification triggers backdated PAYE liability on the engaging business.

How much does PAYE non-compliance cost?

Late RTI submission penalties start at £100 per month and scale to £400 for repeated failures, while late payment of deducted tax and NI attracts 5% charges plus daily interest. Deliberate non-compliance can result in criminal prosecution with unlimited fines and potential imprisonment. The total cost often exceeds the annual cost of professional payroll services.

Methodology and disclosure

This guide is based on HMRC PAYE guidance, compliance statistics from HMRC’s annual report, and penalty data from parliamentary tax committee publications.

We reviewed current PAYE rates, RTI submission requirements, and penalty structures as of April 2026.

Whichapp is an independent comparison site for payroll and employment services. We do not provide PAYE advice or payroll services.

This guide explains the system but does not replace professional advice for your specific situation.

We did not test payroll software directly or interview HMRC compliance officers. Our analysis draws on published guidance and reported business experiences.