In-house payroll vs EOR for UK sick pay compliance

Your UK payroll team just processed SSP for 15 employees. Three had linked absences from earlier this year. One returned on a phased basis. Another hit the 28-week cap mid-month. Did your payroll software handle the Average Weekly Earnings calculations correctly? Did HR document the qualifying days accurately? And when the April 2026 SSP reforms arrive, who's responsible for updating every calculation, process, and contract?

The decision between running UK payroll in-house and using an Employer of Record isn't just about cost anymore. The upcoming SSP reforms introduce day-one entitlement, new 80% AWE calculation methods, transitional rules for existing absences, and a new enforcement body with real teeth. For mid-market companies with UK employees, this isn't a payroll configuration change. It's a compliance architecture decision.

Teamed is the trusted global employment expert for companies who need the right structure for where they are, and trusted advice for where they're going. This guide gives you an honest framework for deciding whether to build UK payroll capability internally or use an EOR, specifically in light of the complexity the SSP reforms add. We'll tell you when in-house makes sense and when it doesn't, because the right answer depends on your situation, not ours.

The SSP basics that catch payroll teams off guard

Under current UK SSP rules, SSP is paid from the 4th qualifying day of sickness, creating a three-day waiting period before statutory payments begin.

UK SSP can be paid for up to 28 weeks per period of sickness entitlement, after which SSP entitlement typically ends and employees may transition to other benefits.

Two sickness absences are treated as a single linked period if the gap between them is 8 weeks or less, which can change eligibility calculations and waiting day treatment.

Teamed's Crossover Economics framework treats a 50-employee UK headcount as a common mid-market inflection point where entity-based payroll often becomes financially competitive with EOR.

UK employers must operate PAYE to report pay and deductions to HMRC through payroll, and statutory payments like SSP must be reflected accurately in payroll reporting outputs.

Here's what we've learned: one complex sick pay case can eat up a week of your team's time, especially when you're correcting months of historical payments and explaining it to employees who've lost trust.

What the April 2026 reforms mean for your payroll ownership decision

The reforms aren't just a rate adjustment. They fundamentally change how SSP eligibility works and how employers must calculate payments, bringing up to 1.3 million employees into SSP eligibility who previously received nothing. Day-one entitlement eliminates the previous qualifying period, meaning every employee is eligible for SSP from their first day of employment. The new 80% AWE calculation method requires payroll systems to compute statutory entitlements using a defined reference period and documented earnings inputs.

Transitional rules add another layer. Employees with absences spanning the reform date need different treatment than those whose sickness begins after April 2026. Your payroll system needs to handle both calculation methods simultaneously during the transition period. And the new Fair Work Agency brings enforcement powers that previous regulators lacked, including powers to investigate breaches and issue civil penalties.

For in-house payroll teams, this means software updates, process redesign, HR training on new eligibility rules, and ongoing monitoring of enforcement guidance. For EOR arrangements, the provider absorbs this complexity, but you need to understand what that actually means for your compliance exposure.

What you actually need to own if you run UK payroll yourself

Running compliant UK payroll internally requires more than software. You need an integrated system where payroll, HR, and legal functions work together on statutory payments. A single missing absence notification can cause an incorrect SSP decision even when your payroll calculation logic is correct.

Your payroll software needs configuration for the 80% AWE calculations, including the ability to handle the new 8 weeks reference period and earnings inputs. Most payroll systems require updates when calculation logic changes, and lead times can range from weeks to months when changes require new data fields, regression testing, and revised approval workflows. You can't assume your current software will handle the reforms automatically.

HR teams need training on the transitional rules and linked absence periods. When an employee has two sickness absences separated by 8 weeks or less, they're treated as a single linked period. This affects waiting days, entitlement calculations, and recordkeeping. Your HR team needs to understand these rules well enough to document absences correctly and flag edge cases for legal review.

You also need a budget for legal advice on complex situations. Phased returns, contractor reclassification, employees hitting the 28-week cap, disputes over qualifying days. These aren't payroll configuration issues. They require someone who understands UK employment law and can advise on the specific situation.

What an EOR actually owns (and what they don't) for UK sick pay

An Employer of Record becomes the legal employer of your UK-based workers. The EOR's UK employing entity runs payroll and statutory payments, assumes day-to-day compliance execution, and handles the administrative burden of SSP calculations, documentation, and HMRC reporting.

The EOR takes responsibility for updating payroll systems when regulations change. When the April 2026 reforms arrive, the EOR rolls those updates into its standard payroll operations and templates. Your team doesn't need to manage software configuration, regression testing, or process redesign. The EOR's operational team makes and documents SSP decisions within their payroll controls.

Employment contracts and handbook updates come through the EOR. When SSP rules change, the EOR updates contract templates and policy documents. You don't need internal legal review of every change, because the EOR has already done that work across their client base.

The shared responsibility model matters here. The EOR handles payroll execution, but you're still responsible for timely absence reporting. If your manager doesn't notify the EOR that an employee is sick, the EOR can't process SSP correctly. Most EOR contracts allocate some responsibilities to the client and limit the provider's financial liability. A thorough EOR evaluation helps identify these allocation gaps before they become compliance issues. Teamed's EOR evaluation checklist treats liability caps below 12 months of fees as a material commercial risk, because capped remedies can be smaller than the total cost of correcting multi-employee payroll underpayments plus advisory spend.

The costs that surprise you in each model

The cost comparison isn't as simple as EOR fees versus payroll software subscriptions. You need to account for the full cost stack on both sides.

In-house payroll costs include payroll software licensing, internal staff time for payroll processing and compliance monitoring, HR time for absence management and documentation, legal advisory fees for edge cases and regulatory changes, and the cost of errors. When you underpay SSP, you need to correct historical payments, potentially deal with employee complaints, and document your remediation for any enforcement inquiry, with employer SSP costs expected to increase by approximately £15 per employee annually under the new reforms.

EOR costs are typically a per-employee monthly fee that covers payroll processing, statutory payments, employment contracts, and compliance management. The fee is predictable and scales linearly with headcount. But you need to examine what's actually included. Some EORs charge separately for contract amendments, offboarding, or compliance consultations.

Teamed's Crossover Economics framework provides a structured way to compare these costs. The calculation method is straightforward: multiply your annual EOR cost by projected years, then compare against entity setup cost plus ongoing annual entity costs. For UK operations specifically, the entity threshold is typically 10 or more employees if your team operates in English. Below that threshold, EOR is usually more cost-effective. Above it, the economics start favouring your own entity.

But cost isn't the only factor. The question is whether you have the internal capability to manage SSP compliance at your current headcount, and whether you want to build that capability for the future.

When does in-house UK payroll make sense?

Choose in-house UK payroll when you already operate a UK entity and can assign named owners for SSP policy, payroll configuration, HR absence processes, and legal review of edge cases. You need people who are accountable for each part of the compliance chain, not just software that runs calculations.

In-house makes sense when UK headcount is stable at 50 or more employees and you can amortise payroll software, internal controls, and external legal support across a larger base. The fixed costs of maintaining compliant payroll infrastructure become reasonable when spread across enough employees.

You should also consider in-house when you need bespoke UK benefits, complex pay elements, or integrations with finance systems that are difficult to implement through an EOR's standardised payroll and benefits stack. EORs work from templates. If your compensation structure doesn't fit those templates, you'll spend more time on workarounds than you would building your own capability.

The key requirement is operational readiness. Do you have HR and legal resources, either internal or outsourced, capable of managing local compliance? Can you monitor regulatory changes and update your processes before enforcement catches up with you? If the answer is yes, in-house payroll gives you control over policy detail and direct accountability for compliance outcomes.

When does an EOR make sense for UK sick pay?

Choose an EOR when you have fewer than 50 UK employees and no dedicated UK payroll or HR capability to manage SSP eligibility decisions, absence evidence handling, and audit-ready records at scale. The complexity of your situation often determines whether an EOR is the right structural choice. The complexity of SSP compliance doesn't scale linearly with headcount, but your ability to manage it does.

An EOR makes sense when you don't have a UK entity and need compliant UK employment and payroll in weeks rather than the time required to incorporate, register, and operationalise payroll governance internally. Entity establishment in the UK typically takes 2-4 months. If you need to hire now, an EOR gets you there faster.

Consider an EOR when enforcement risk is a board-level concern and you need a clearer operational accountability model for statutory sick pay processing, documentation, and change management after regulatory updates. With an EOR, there's a named party responsible for payroll execution. When something goes wrong, you know who to call.

The EOR model also works when you're entering a new market and want to validate product-market fit before committing to entity infrastructure. You can hire through an EOR, see how the UK market develops, and then decide whether to establish your own entity based on actual headcount and growth trajectory.

Is there a middle ground between EOR and in-house?

Yes. Some companies use an EOR to enter the UK and then transition to in-house payroll once they reach scale. This hybrid approach works as long as the transition is planned, not reactive.

Choose a hybrid approach when you're entering the UK with fewer than 20 employees and expect to exceed 50 employees within 12-24 months. Planned graduation reduces disruption compared with a reactive switch. You can use the EOR period to understand UK employment requirements, build relationships with local advisors, and prepare your internal systems for the transition.

The graduation model, Teamed's proprietary framework for guiding companies through sequential employment model transitions, treats this as a natural progression. You start with the structure that fits your current situation, then evolve as your needs change. The key is maintaining continuity through a single advisory relationship, so you don't lose institutional knowledge when you transition from EOR to your own entity.

What you want to avoid is the graduation cliff, where you outgrow your EOR but haven't prepared for the transition. Suddenly you need to find an entity setup specialist, a local payroll provider, and a compliance advisor. Each transition introduces risk, cost, and a break in the advisory relationship. Planning the transition in advance eliminates that cliff.

What should you check in an EOR contract for SSP compliance?

EOR contracts vary significantly in how they allocate compliance responsibilities. You need to understand exactly what you're buying before you sign.

Check the liability cap. Most EOR contracts limit the provider's financial liability for compliance errors. If that cap is below 12 months of fees, you're carrying more risk than you might realise. A multi-employee SSP underpayment, plus the cost of correction, plus advisory fees to manage the remediation, can easily exceed a capped remedy.

Understand the client notification obligations. EOR contracts commonly require you to report absences within a specific timeframe. If you miss that window, the EOR may not be responsible for incorrect SSP processing. Make sure your managers know what they need to report and when.

Ask about change management. When the April 2026 reforms arrive, how will the EOR communicate changes to you? Will they update contracts automatically, or do you need to request amendments? What's the timeline for payroll system updates, and what happens if the update is delayed?

Review the remediation commitments. If the EOR makes an SSP error, what's the process for correction? Who pays for the additional advisory work? How quickly will they resolve the issue? These details matter when something goes wrong.

A decision test you can take to your CFO

The decision framework has five criteria. You should consider transitioning to your own entity when you meet all of them.

First, employee concentration. Have you reached or exceeded 10 employees in the UK? That's the threshold where entity economics typically become competitive with EOR for UK operations.

Second, long-term commitment. Are you planning a 3-year or longer presence in the UK market with stable or growing headcount? Entity setup costs require multi-year presence to justify the investment.

Third, economic viability. Do your annual EOR costs multiplied by expected years exceed entity setup cost plus ongoing annual costs? Run the actual calculation with your real numbers.

Fourth, control requirements. Do you need direct control over local operations, bespoke benefits design, or integrations with finance systems that EORs can't easily accommodate?

Fifth, operational readiness. Do you have HR and legal resources capable of managing local compliance? If not, do you have the budget to acquire them through outsourced support?

If you meet all five criteria, in-house payroll is likely the better choice. If you don't meet them, or if any of the red flags apply, stay with EOR until your situation changes.

Signs you're not ready to run UK payroll yourself

Stay with EOR if you're in your first 1-2 years in the UK market while validating product-market fit. The regulatory environment is stable, but your business outlook might not be. Entity setup costs don't make sense if you might exit the market.

Stay with EOR if you lack local HR and legal expertise and have no budget to acquire it through outsourced support. Running compliant payroll requires more than software. Without the people to manage it, you're creating risk.

Stay with EOR if your UK employees are spread across the country with high turnover, suggesting headcount may not remain stable. The economics of entity establishment assume you'll maintain a certain employee count over time.

And stay with EOR if you simply don't have the internal resources to oversee local entity compliance. Someone needs to monitor regulatory changes, manage relationships with local advisors, and ensure your processes stay current. If that person doesn't exist in your organisation, EOR is the safer choice.

Making the right decision for your UK team

The April 2026 SSP reforms add complexity that tips the balance for many mid-market companies. Day-one entitlement, new calculation methods, transitional rules, and a new enforcement body mean payroll teams need deeper UK employment law knowledge than before. The question isn't whether you can handle SSP compliance. It's whether you want to build that capability internally or outsource it to a provider who already has it.

The honest answer depends on your situation. If you have 50 or more UK employees, a dedicated HR function, and established payroll infrastructure, in-house makes sense. If you have fewer than 50 employees, no UK entity, or your HR team lacks UK employment law expertise, an EOR is likely the more cost-effective and lower-risk option.

If you're not sure which model fits your situation, book your Situation Room with Teamed. We'll review your UK employment setup and give you an honest assessment of whether EOR, in-house payroll, or a planned transition between them makes the most sense for where you are and where you're going.