Switching Payroll Providers Mid-Tax Year: UK Employer Checklist

You can switch payroll providers mid-tax year, but you need a controlled migration.

The risk is not only moving employee names and tax codes. It is preserving year-to-date figures, pension settings, statutory payment history and RTI continuity so the next payroll run is accurate.

This guide gives UK employers a practical migration sequence, the records to reconcile and the questions to answer before the first live run. It is general payroll information rather than tax, legal or accountancy advice. Confirm the migration plan with the outgoing provider, incoming provider and the person responsible for your PAYE scheme.

Last reviewed: 5 August 2026 against current GOV.UK and HMRC guidance.

When mid-year switching makes sense

Employers usually consider switching mid-tax year when:

• the current system creates too much manual admin;
• payroll depends on disconnected rota or timesheet tools;
• the business is growing across sites;
• errors keep appearing after payroll;
• the payroll owner cannot see manager approvals;
• the business needs better mobile access;
• implementation support is available.

If the current process is failing, waiting until April can mean several more months of bad payroll data.

Choose the switch date around payroll risk

A mid-year migration does not have to begin on 6 April. The safer date is the one that leaves enough time to receive the outgoing records, configure the new system, reconcile the opening balances and investigate differences before payday.

Before agreeing the date, confirm:

• the final payroll that the outgoing provider will process;
• the first payroll that the new provider will process;
• the cut-off for starters, leavers, pay changes and variable hours;
• who will make any correction discovered during the transition;
• whether pension and payment files need separate setup or approval;
• when the parallel comparison will be available;
• who has authority to approve the first live run.

Avoid treating the software setup date as the migration date. A system can be configured while data ownership, corrections and final approval remain unresolved.

What to export before switching

Build a migration pack with:

• employee personal details;
• National Insurance numbers;
• tax codes;
• pay rates and pay frequency;
• payroll IDs;
• starter and leaver dates;
• year-to-date taxable pay;
• year-to-date tax and National Insurance;
• pension contributions and pension scheme settings;
• statutory sick pay, maternity pay and other statutory payment records;
• student loan and postgraduate loan deductions;
• attachment of earnings orders;
• holiday balances if managed in the payroll process;
• previous FPS and EPS submission records;
• P45 details for leavers in the current year.

Do not rely on memory or screenshots. Export clean records.

Keep the original export unchanged and work from a controlled copy. Record when it was produced, which payroll it follows and who supplied it. That gives the migration team a stable starting point if a balance or employee record later needs to be traced.

Use the Workmax payroll hub to identify related year-end, starter, leaver and payroll-control guidance while building the migration pack.

Assign an owner to each migration control

Moving payroll is easier when responsibility is explicit. A small migration can still use a simple ownership table:

Control	Evidence to retain	Suggested owner
Outgoing payroll cut-off	Final processed period and unresolved corrections	Current payroll owner
Opening balances	Source export and reconciliation result	Payroll migration lead
Employee and employment setup	Exception list and approval	HR or payroll
Pension configuration	Scheme, worker category and contribution checks	Payroll and pension owner
RTI continuity	PAYE references, payroll IDs and submission plan	Payroll compliance owner
Variable pay inputs	Approved hours, overtime and adjustments	Operational approvers
First live run	Parallel comparison and final sign-off	Named senior approver

The same person can own several controls, but no control should be assumed to belong to “the provider” without a named contact and an agreed hand-off.

HMRC timing checks

GOV.UK says employers should send a Full Payment Submission on or before payday. It also says monthly PAYE bills are due by the 22nd of the next tax month when paying electronically, or the 19th if paying by cheque through the post.

During a migration, the practical rule is simple: do not switch so close to payday that there is no time to compare the old and new results.

The migration plan should preserve the usual payment date used for reporting. If an FPS needs correcting, follow current HMRC guidance and retain the reason for the correction. Do not create a new payroll identity for an existing employment merely to make the import easier; confirm how the new system will preserve the identifiers and year-to-date history needed for continuity.

PAYE payment deadlines continue during the switch. Changing provider does not move the employer's deadline or transfer responsibility away from the employer.

Parallel run checklist

Before the first live pay run, compare:

• gross pay;
• taxable pay;
• PAYE tax;
• employee National Insurance;
• employer National Insurance;
• pension deductions;
• net pay;
• statutory payments;
• student loan deductions;
• leaver final pay.

Any difference should have a written explanation.

Do not limit the comparison to totals for the whole payroll. A matching grand total can hide differences between employees, employments, pay elements or deductions. Compare each employment, then reconcile the control totals.

Use synthetic test records when checking configuration before live data is available. Include at least a straightforward employee, a starter or leaver, a worker with variable pay and a record with a pension or statutory-pay history. Synthetic cases test the workflow without copying real payroll information into an uncontrolled environment.

Protect year-to-date and identity continuity

The incoming system needs to distinguish an existing employment from a genuinely new starter. Confirm how it will handle:

• payroll IDs and any change that must be reported;
• tax, National Insurance and taxable-pay balances;
• director or irregular-payment indicators where relevant;
• student and postgraduate loan deductions;
• statutory-payment history and remaining entitlement inputs;
• pension membership, postponement and contribution history;
• leavers already reported in the tax year;
• previous corrections and the audit evidence behind them.

Do not delete an inconvenient difference or overwrite the source export. Put it on an exception list, assign an owner and record the resolution.

Check the first live run after submission

Approval is not the end of the migration. After the first live run:

1. Confirm the payment file or payment instruction matches the approved payroll.
2. Confirm payslips reflect the approved results.
3. Check the FPS submission response and retain the accepted submission evidence.
4. Reconcile the liability shown in the payroll reports with the amount expected for HMRC.
5. Check pension outputs and any separate pension submission process.
6. Review rejected records, warnings, late changes and manual corrections.
7. Keep a short post-run issue log and confirm which items must be checked again next period.

Run an additional reconciliation after the next payroll. Some migration errors only become visible when cumulative values, statutory history or recurring deductions are used again.

Fix the workflow, not just the provider

A payroll migration is wasted if the same messy inputs continue.

Use the switch to decide:

• who approves hours;
• when site managers must close timesheets;
• how late corrections are handled;
• how new starters are checked;
• how leavers are processed;
• where payroll exceptions are reviewed;
• who owns final sign-off.

The right system should make those steps visible.

The best outcome is not merely that the new provider produces a payslip. It is that the employer can show where each input came from, who approved it, what was submitted and how any later correction was controlled.

How Workmax helps

Workmax helps employers connect HR, scheduling, time tracking and payroll so approved workforce records can move into payroll without spreadsheet reconstruction. Managers still need to approve inputs, review exceptions and sign off the payroll result.

Read migrating to Workmax, compare pricing or book a payroll migration demo.

Sources

• GOV.UK reporting payroll to HMRC
• GOV.UK send your final payroll report
• GOV.UK pay employers' PAYE
• GOV.UK HMRC-recognised payroll software guidance