Is it risky to switch payroll software mid-tax year?

Are you looking to switch your payroll software mid-tax year? Changing payroll software partway through the tax year raises a fair few questions. Will employees be paid correctly? Will HMRC end up with two records for the same person? Will P60s add up in April?

Moving payroll software is no small decision.

After all, payroll is at the heart of any business, ensuring staff are paid correctly and on time.

However, the uncertainty shouldn’t act as a deterrent to switching, as, with a rock-solid plan, the move is relatively simple and pain-free.

A mid-year switch is perfectly manageable, providing you move the right data and check it before your first live pay run.

This guide aims to help demystify the idea of switching payroll software mid-tax year, explaining what can go wrong, what data to move, when timing matters and how to switch without disrupting a pay run.

You’ll find links to the GOV.UK guidance you’ll need along the way.

Key takeaways

• Switching payroll software mid-tax year is allowed and common. Risk arises from moving data incorrectly, not from the timing.
• Your new payroll software needs accurate year-to-date figures for every employee.
• Only one payroll system should send a Full Payment Submission (FPS) for each pay period.
• Parallel payroll runs help catch differences before they reach payslips.
• Switching at the start of the tax year (6 April) is simpler, but waiting isn’t always the better option.

Is it risky to switch payroll software mid-tax year?

It’s not risky to switch payroll software mid-tax year, as long as you transfer year-to-date figures accurately, agree the first pay period your new system will run, and run at least one parallel payroll before you go live.

There are no restrictions from HMRC on changing payroll software during the tax year, and your PAYE reference stays the same.

Most mid-year switching problems tend to come from a rushed data handover, not the actual switching date.

Switching on 6 April is the simpler option because year-to-date figures start at zero, meaning you don’t need to import year-to-date pay, tax and NI.

However, you’ll still need to move employee details, pay elements and tax codes, plus any ongoing pension, student loan and statutory payment data.

Mid-year, by contrast, your new payroll software has to pick up each employee’s pay, tax and National Insurance (NI) exactly where the old system left off.

That said, while switching at the start of a tax year is simpler, waiting has costs of its own.

Unlike a wobbly shelf you keep meaning to fix, your payroll is not an area where you can afford to cut corners or settle for a system that isn’t quite right.

If your current payroll software causes errors, takes hours each pay run or leaves you unsure about compliance, those problems shouldn’t wait until April.

Another consideration with an April move is that it lands on top of your year-end tasks, such as the final submission for the year and P60s.

For many payroll professionals, payroll year end is an incredibly busy period, and adding a software switch on top of all their responsibilities isn’t always feasible.

What can go wrong when you switch payroll software mid-year?

Most mid-year switching problems fall into six areas: year-to-date figures, duplicate FPS submissions, payroll IDs, tax codes/NI categories, pension data and untested integrations.

The good news is that each one is preventable with some planning and preparation.

This table covers each of the high-risk areas and how to prevent errors.

Payroll IDs often catch employers out.

If your new payroll software can’t keep the same IDs, HMRC advises you to enter the old and new IDs and set the ‘Payroll ID changed’ indicator in your FPS.

If you don’t, your PAYE bill may be calculated incorrectly and employee records duplicated.

Don’t set transferred employees up as new starters either.

HMRC’s April 2026 Employer Bulletin warns that submitting a start date or a starter declaration, instead of using the ‘Payroll ID changed’ indicator, also creates duplicate employments.

See GOV.UK’s guidance on changing payroll software and the payroll information to report to HMRC.

What payroll data do you need to move mid-year?

In your new payroll software, you need everything the system requires to carry on each employee’s calculations from where the old system stopped.

This includes personal details, tax codes, year-to-date pay/deductions, pension details, statutory payments and your pay elements, plus a few employer-level figures.

Use this as a checklist for the data required:

• Employee details such as name, address, date of birth, NI number, start date and bank details
• Tax codes and week 1/month 1 basis
• Year-to-date gross pay and taxable pay
• Year-to-date tax, and employee and employer NI, by NI category
• Student and postgraduate loan plan types and deductions to date
• Pension contributions to date, scheme details, auto-enrolment assessment and postponement dates and opt-in or opt-out status
• Statutory payments to date, such as Statutory Sick Pay (SSP), Statutory Maternity Pay (SMP) and Statutory Paternity Pay (SPP), and any amounts already recovered through an Employer Payment Summary (EPS)
• Pay elements such as pay rates, overtime, salary sacrifice, attachments of earnings and payrolled benefits
• Pay frequencies, pay dates and cut-off dates
• Old payroll IDs
• Holiday balances, if your payroll calculates holiday pay

We recommend you export your payroll data in a format you can open and check, such as CSV or a spreadsheet.

Note that you must also keep PAYE records for three years from the end of the tax year they relate to; make sure you can still access your old records even after you leave (GOV.UK: keeping PAYE records).

Should you switch payroll software in April or mid-year?

If nothing is going wrong with your current payroll software and you simply want to upgrade, switching in April is the easier option.

A mid-year switch is best for those with systems that are causing errors, creating additional admin or losing support.

While a mid-year move adds an extra step (importing and checking year-to-date figures), it saves you months of relying on an inadequate system.

Whether you choose to move at the start of the tax year or mid-year, avoid the following:

• Your busiest pay periods
• Annual pay reviews
• Seasonal hiring peaks
• The weeks around your pension re-enrolment date

How do you switch payroll software without disrupting a pay run?

The first step is to confirm your contract terms and the first pay period your new system will run.

Then check your data and run a parallel payroll before you go live.

Ensure only one system sends the FPS for each pay period, and keep your old system in play until you’ve reconciled the first month’s PAYE bill.

These steps help define the switching process:

1. Confirm your current contract notice period and your rights to export data.
2. Choose the first pay period your new system will run, and agree in writing with your old provider which period is the last one it files with HMRC.
3. Export your data and check it against the checklist above.
4. Set up the new system and import your data.
5. Run a parallel payroll. Process the same period in both systems and compare gross pay, tax/NI, pension contributions and net pay for every employee to ensure everything lines up. Only one system should submit to HMRC for that period.
6. Tell your pension provider about the change and test the contribution file. The Pensions Regulator explains your re-enrolment duties.
7. Tell employees what’s changing, such as the payslip layout or login, and what isn’t, such as their pay date and pay.
8. Run your first live payroll in the new system and send the FPS.
9. From the 10th of the following tax month, check your HMRC online account to confirm the amount due for that period matches your payroll and hasn’t been duplicated.

For the full switching process, including what to look for in support and implementation, see our payroll software switching guide.

How do you move from separate HR and payroll tools to one platform without disrupting a pay run?

Many businesses are looking to connect HR and payroll, which often prompts the search for new software.

If this scenario applies to you, look to do the following.

Move payroll software first and run a parallel payroll before you switch off your old systems.

Then connect HR, either through an open API or a pre-built connector, so employee changes, such as new starters, leavers and salary changes, flow directly into payroll.

This approach helps ensure pay runs are stable while systems undergo change.

Once HR and payroll are integrated, you enter a change once instead of rekeying it in two systems.

Staffology HR with Staffology Payroll is our integrated option, with employee data syncing between the two.

If you’re deciding between HR software with built-in payroll and two connected systems, our guide to HR software with built-in payroll vs integrated compares the two options.

What should you ask a payroll provider before you switch?

Switching payroll software is a big change, and you need to understand how your vendor handles the move.

Take these questions to each provider to better understand their approach to managing a mid-year switch:

• Do you support mid-year moves, and how do you import year-to-date data?
• What does implementation include, and what costs extra?
• Do you offer a parallel run?
• Who checks the imported data before go-live?
• How long does a typical move take for a payroll like ours?
• Which pension providers and accounting systems do you connect to?
• What support do we get during the first live pay run?

You also need to establish whether the software is HMRC-recognised, which you can check on GOV.UK’s list of recognised payroll software.

Our guide to how much payroll software costs in the UK covers the costs to budget for.

How does Staffology Payroll support a mid-year switch?

You can move to cloud payroll software, Staffology Payroll, at any point in the tax year, not just in April.

Our team has already helped hundreds of businesses switch mid-year.

• Getting started: if you have fewer than 50 employees, you can set up Staffology Payroll yourself using our training videos and knowledge base. For larger payrolls, we recommend guided implementation, where we agree a timeline with you, set up the software, help import your data and train your team.
• Parallel runs: you can add a parallel payroll run before go-live to check results against your current system.
• Data transfer: our CSV import templates check your data as you import it, and our step-by-step transfer guides explain each method.
• Support: our specialist team is available by phone, live chat and support ticket, and our knowledge base is available 24/7.

Talk to us about switching to Staffology Payroll or download the payroll software switching guide.

Switching payroll software mid-tax year FAQs

Frequently Asked Questions (FAQs)

Do I need to tell HMRC I’m changing payroll software?

No, you don’t need to tell HMRC that you’re changing payroll software. You don’t need to register again or apply for a new PAYE reference. Keep reporting through your FPS as usual, from the new system. If your employees’ payroll IDs change, enter the old and new IDs and set the “Payroll ID changed” indicator so HMRC can match their records.

Will my PAYE reference change?

No, your PAYE reference won’t change if you switch payroll software. Your PAYE reference belongs to your employer PAYE scheme, not your software, so it stays the same when you change payroll software or provider. Enter it in your new system exactly as HMRC issued it.

Who issues P60s if I switch mid-year?

If you switch payroll software mid-year, your new system issues P60s for the full tax year, as it should hold the imported year-to-date figures. You must give a P60 by 31 May to every employee on your payroll on 5 April (GOV.UK: P60s).

Who sends the final submission for the tax year?

The payroll system you’re using at the end of the tax year sends the final FPS or EPS for the year. So, after a mid-year switch, that’s your new payroll system. Your old system shouldn’t send anything for periods after you’ve changed.

How long does it take to switch payroll software?

How long it takes to switch payroll software largely depends on how many employees you have, how clean your data is and whether you run a parallel payroll (which is recommended). Smaller payrolls can be set up quickly. For larger payrolls, speak with your provider for a tailored timeline that includes data checks and at least one parallel run.

Will employees notice any change?

Employees may notice a slight change, as they’ll likely be using a different system to access their payslips, which may look different and will require a new login. However, their pay date and pay should stay the same. It’s best practice to tell them what’s changing and what isn’t before the first live pay run.

What happens to historical payslips?

You must keep PAYE records for three years from the end of the tax year they relate to. Minimum wage records must be kept for longer, at least six years, so check your retention rules before deleting any old exports.To ensure you have a record of historical payslips, export them and any reports from your old system before your access ends. It’s also worth checking how long you can keep access to your old system once you make the move.

Does switching affect my auto-enrolment re-enrolment date?

No, switching doesn’t affect your auto-enrolment re-enrolment date. Re-enrolment happens every three years, and you choose the date within a six-month window around the third anniversary of your duties start date, or of your last re-enrolment date if you’ve re-enrolled before. Changing payroll software doesn’t reset or move it. Just make sure your new payroll system and your pension provider both have the right date saved, and try not to switch over in the few weeks around it.