Parallel Run Guide
Rebecca Russell avatar
Written by Rebecca Russell
Updated over a week ago


The aim of a parallel run is to allow you to become familiar with PayFit whilst ensuring a smooth onboarding and accurate data. We understand that transferring all of your data from one source to another can require a lot of work. This guide, along with the support of your Account Manager & Onboarder, will help you make the transition as seamless as possible.

If you have all the information you need and are comfortable with inputting this data yourself then you can skip ‘Collecting Your Data’. Please do continue to follow the instructions outlined in the ‘Pre-payroll Checks

This guide will be broken down into 3 main steps:

  1. Collecting Your Data

  2. Pre-payroll Checks

  3. Post-payroll Checks

Collecting Your Data

Giving us the right onboarding data is important to ensure your employee and HMRC records are correct during your parallel run and in future months. Any missing or incorrect data can lead to discrepancies between your HMRC account and PayFit.

This section is split into:

  1. Employee Data

  2. Company Data

Employee Data

We will ask for this information in your onboarding spreadsheet. Most of the data we need will usually be on your employees payslip. Not all payslips contain the same information but typically you can find the following on the payslip:

  • Taxable income

  • Tax paid

  • Employee NIC paid

  • Student Loan deductions

Your previous provider should also be able to provide you with reports containing this information if you cannot find this on the payslips.

Less common information:

This table will highlight some of the information that is not always on payslips, where else you can find it and also some common mistakes we see.

💡 Please ask your previous provider for a copy of the last FPS they submitted - you should use this as the source of truth for data that you cannot find on the payslip 💡

If you are still unable to find some of the data we are asking for please let your Onboarder know and they will be able to provide you with some more guidance.

Company Data

When you have access to your PayFit account you will be asked to complete the Onboarding checklist. Here you will be asked to input key company data. It is important you correctly report this information as any incorrect or missing data may result in a discrepancy between your PayFit and HMRC accounts.

💡 Please ask your previous provider for a copy of the last EPS they submitted before onboarding as this will have most of the required information💡

If you are still unable to find some of the data we are asking for please let your Account Manager or Onboarder know and they will be able to provide you with some more guidance.

🚀 Pre-Payroll Checks 🚀

After all of your data has been uploaded to PayFit please conduct some final checks before running payroll. Here we are wanting to make sure that your Parallel run with PayFit matches with your live payroll.


1️⃣ Do employee’s net payments match?

Please ensure the total net of all employees matches with your live payroll. If there is a difference you should use the PayFit reports to identify the employees causing the difference and raise this with your Onboarder.

2️⃣ Do all the elements of your P32 (aka Employer Payment Summary) match?
This includes:

  • Income tax due

  • Employee & Employer NIC due

  • Student & Postgraduate Loan deductions

  • Recoverable amounts (SMP, SPP etc..)

  • Apprenticeship Levy charge (if applicable)

  • Employment Allowance (if applicable)

💡 Please check both Monthly and YTD reports. Even if your Monthly reports match a HMRC discrepancy may still arise if the YTD figures are not the same 💡

3️⃣ Any missing data?

Please review this onboarding report to identify any missing data.

Here are the key fields to look out for:

  • Employees in a student loan plan but have no YTD figure

  • Employees on parental leave (not the first month) with no YTD figure

  • Employees missing previous employment data who have a starter declaration of B or C

  • Employees missing current employment YTD data (tax, NI etc) if not onboarding in April

🚀 Post-Payroll Checks 🚀


1️⃣ HMRC account reconciliation:

Please follow the instructions on this Support Centre article.

Conducting this check will identify any differences in non-cumulative figures.

2️⃣ Post-payroll changes:
Have you made any post-payroll changes with your current provider that need to be reported to your Onboarder?
EG: Forgot to add a bonus before running payroll that was then added after payroll had been closed.

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