If you employ anyone in the UK, PAYE Real Time Information (RTI) is the system you use to tell HMRC about pay, tax and National Insurance every single time you run payroll. Unlike the old annual P35 process, you submit data on or before each payday. This guide covers the FPS, the EPS, the payment dates, and the penalties for slipping up.

What RTI actually is

RTI is the data feed between your payroll software and HMRC. Each pay run produces one or two submissions:

  • Full Payment Submission (FPS) - sent on or before each payday, listing every employee’s pay, tax, NIC, student loan and pension data
  • Employer Payment Summary (EPS) - sent monthly when you have adjustments such as statutory pay recoveries, the Employment Allowance, or a nil payroll month

You cannot file by spreadsheet or paper. HMRC requires recognised payroll software, including HMRC’s own free tool for employers with fewer than ten staff.

The monthly cycle

DateAction
On or before each paydaySubmit FPS
19th of following monthEPS due (if any adjustments)
22nd of following monthPAYE and NIC payment due (electronic)
19th of following monthPAYE and NIC payment due (postal cheque)
5 AprilTax year end
19 AprilFinal FPS or EPS for the tax year
31 MayP60s issued to employees
6 JulyP11D and P11D(b) due
22 JulyClass 1A NIC payment due

Quarterly payment is allowed if your monthly PAYE bill averages under £1,500.

What goes in an FPS

Each FPS line covers one employee and includes:

  • Personal details and NI number
  • Pay frequency and payment date
  • Gross pay, taxable pay and pay-to-date totals
  • Tax code and income tax deducted
  • Employee and employer NIC, plus letter
  • Student loan deductions and plan type
  • Pension contributions (employee and employer)
  • Statutory payments (SSP, SMP, SPP, ShPP, SAP)
  • Year-to-date totals across every field

The data flows into the employee’s HMRC personal tax account in near real time, which is why coding notices and starter information must be accurate from day one.

Penalties

OffencePenalty
Late FPS (1-9 employees)£100 per month
Late FPS (10-49 employees)£200 per month
Late FPS (50-249 employees)£300 per month
Late FPS (250+ employees)£400 per month
Late payment1-4% surcharge depending on frequency
Inaccurate returnUp to 100% of additional tax due

The first late FPS in a tax year is usually treated leniently. Repeat offenders face escalating charges and HMRC compliance reviews.

Common RTI mistakes

  • Filing the FPS after payday rather than on or before
  • Forgetting an EPS for the Employment Allowance claim
  • Reporting a leaver after the next pay period rather than on the final FPS
  • Using the wrong NI category letter for under-21s, apprentices or veterans
  • Failing to reconcile the payroll journal to the FPS each month, leading to year-end mismatches

Year-end and beyond

The year-end process under RTI is much lighter than it once was. You confirm the final FPS, issue P60 forms, file P11D for benefits, and start the new tax year codes. Connect your bookkeeping to payroll so the payroll journal entries flow through automatically. The official HMRC PAYE for employers hub is the definitive reference. See pricing to run RTI-compliant payroll alongside your accounts.