Umbrella, PEO or CIS: how to choose the right contractor engagement model

Most UK recruitment agencies have a preferred way of paying contractors. The problem is that contractor engagements are not all the same, and using the wrong model for a given situation creates compliance risk, contractor confusion and occasionally a conversation with HMRC that nobody wanted. Choosing the right engagement model starts with understanding what each one actually does.

At a glance

• Umbrella is an employment model. The umbrella company employs the contractor, processes PAYE and handles employer costs from within the assignment rate. Best for temporary assignments, particularly inside IR35.
• PEO (Professional Employer Organisation) is also a PAYE employment model, but employer costs are calculated and charged separately rather than deducted from the assignment rate. Best where rate clarity for the worker matters, or where an agency wants to fully outsource employment administration.
• CIS (Construction Industry Scheme) is not an employment model. It is a self-employed engagement framework specific to construction work, with tax deducted at source. It is only appropriate where the worker is genuinely self-employed and not subject to supervision, direction or control.
• Limited company is a fourth option for contractors operating outside IR35 through their own Personal Service Company (PSC).

Umbrella employment: how it works

When a contractor engages through an umbrella company, the umbrella becomes the employer. The recruitment agency pays the umbrella an assignment rate, which is set at a level that covers the contractor’s gross pay, employer National Insurance contributions, employer pension contributions, and the umbrella’s margin. The umbrella then runs payroll, makes the statutory deductions and pays the contractor net of income tax and employee National Insurance, along with a clear, itemised payslip.

From the contractor’s perspective, they’re employed. That means they have proper employment rights: statutory sick pay, auto-enrolment pension, holiday entitlement and access to statutory maternity or paternity pay.

When umbrella is the right choice: umbrella is the most widely used model and, in many situations, the most appropriate. It suits contractors working on temporary assignments across the majority of sectors and it’s the standard route for workers inside IR35. If an end client has determined that an off-payroll working (IR35) rule applies, umbrella employment resolves the question of employment status cleanly – the contractor is employed by the umbrella, while PAYE is operated correctly and there’s no risk of a tax liability falling back on the agency or end client.

What agencies need to check: not all umbrella companies operate to the same standard. Compliance failures in the umbrella market – mini umbrella schemes, disguised remuneration, incorrect PAYE operation – can create joint and several liability for agencies under legislation that took effect in April 2026. When adding an umbrella to your Preferred Supplier List (PSL), check for FCSA accreditation, which requires a rigorous annual audit of compliance processes. 

SafeRec real-time payroll auditing provides an additional layer of assurance: every payroll run is checked independently, so agencies and contractors both have confidence that deductions are reaching HMRC correctly. Sapphire has held FCSA accreditation for nine consecutive years and applies SafeRec auditing as standard across all payroll runs.

PEO: how it differs from umbrella

Both umbrella and PEO result in the contractor being employed on a PAYE basis through Sapphire, but the structure of how employment costs are handled is different, and that distinction matters commercially.

In an umbrella arrangement, the assignment rate paid by the agency to the umbrella already includes employer costs. When the worker receives their payslip, the gross taxable pay figure has been calculated after those employer-side deductions – employer NI, Apprenticeship Levy and employer pension contributions – have been taken from the top of the assignment rate. For many contractors this is fine, but for some, particularly those accustomed to a conventional salary, the gap between the rate they were told and the taxable pay figure on their payslip can create confusion and, occasionally, dissatisfaction that gets directed back at the agency.

A PEO model works differently. The worker is offered a standard PAYE rate – a gross salary figure that is clear and straightforward. The employer costs (employer National Insurance, Apprenticeship Levy, holiday pay and pension contributions) are calculated separately and charged directly to the agency. The agency knows what the worker is earning. The worker knows what the worker is earning. There is no deduction from the top of the assignment rate to explain.

For agencies, PEO also means fully outsourcing the employment relationship and payroll administration. Self-billing is available, reducing the invoicing burden. The agency gains the compliance protection of compliant employment without carrying any of the administrative weight.

When PEO is the right choice: PEO suits agencies who want to retain a PAYE employment model for their contractors but want to remove rate-transparency friction with workers. It also works well for agencies who want to fully outsource employment administration and payroll without defaulting to umbrella. Where an agency is placing workers who find umbrella assignment rates difficult to understand, or where there have been complaints about payslip clarity, PEO provides a cleaner, simpler proposition.

The compliance position is identical to umbrella: the worker is employed, PAYE is operated correctly, employment rights are in place. The only meaningful difference is how employer costs are structured and charged.

CIS: how it works and when it applies

CIS is a different category entirely. It is not an employment model.

The Construction Industry Scheme is HMRC’s framework for payments made to self-employed subcontractors working on qualifying construction activities. Under CIS, the paying party – whether a contractor or a recruitment agency acting in that capacity – deducts tax at source before payment. 

For subcontractors registered with HMRC, the deduction rate is 20%. For unregistered subcontractors, the rate is 30%. Those deductions are advance payments towards the subcontractor’s tax liability; they are not employer deductions and they carry no employment rights.

For a worker to be paid under CIS through a recruitment agency, the worker must:

• hold a Unique Taxpayer Reference (UTR) number
• be genuinely self-employed – not employed, not a worker
• be working on activities that qualify under the scheme (construction work on buildings, infrastructure, civil engineering, related installation and demolition)
• not be subject to supervision, direction or control (SDC) by any party in the supply chain

The SDC test is the critical point. If an end client tells a subcontractor what to do, how to do it and when to do it – if the subcontractor is, in any practical sense, working under someone else’s direction – that worker is not genuinely self-employed for CIS purposes. CIS is the wrong model. The correct model is PAYE employment, either through umbrella or directly.

Getting this wrong is a compliance failure. It transfers risk back onto the agency and, in some circumstances, onto the end client. HMRC takes employment status misclassification seriously, particularly in construction where the line between self-employed subcontracting and disguised employment has long been contested.

CIS also has defined sector boundaries. Architecture, surveying, scaffolding hire (without labour), materials delivery and carpet fitting are excluded from the scheme. If a worker’s role falls outside the qualifying activities, CIS is not available regardless of their self-employed status.

When CIS is the right choice: CIS is appropriate for genuinely self-employed subcontractors working on qualifying construction activities who are not under SDC. Sapphire manages the full CIS process – verification with HMRC, deductions, payments and records – so the agency has confidence that the mechanics are correct even when the workforce is self-employed.

If there is any doubt about whether a worker is genuinely self-employed, or whether SDC applies on a specific site, the answer is not to assume CIS is acceptable. The answer is to assess the position correctly before the placement starts.

How to choose: a practical decision framework

The right model depends on four factors: the sector and type of work, the worker’s employment status, whether a role falls inside or outside IR35 and whether rate clarity for the worker matters. 

Use umbrella when: the worker is on a temporary assignment in any sector, the role is inside IR35, the worker is happy to have their employer costs included in the assignment rate, and you want the simplest, most widely understood model.

Use PEO when: rate clarity for the worker matters, you want to outsource the employment relationship completely, or your contractors find umbrella payslips confusing and you’re experiencing friction as a result.

Use CIS when: the worker is genuinely self-employed, the work qualifies under the scheme, and you have confirmed that SDC does not apply. Do not use CIS as a default in construction – apply the employment status test first.

Use limited company (PSC) when: the contractor is outside IR35 and operates through their own Personal Service Company, and the end client has confirmed that IR35 does not apply. This is the fourth option in Sapphire’s suite and suits more experienced contractors with their own tax and accounting arrangements. Sapphire provides limited company accounting to support contractors in this position.

What Sapphire offers across all four models

Most agencies manage contractor engagements through multiple providers – an umbrella for employed contractors, a CIS specialist for construction, an accountancy firm for limited company contractors. That means multiple PSL relationships, multiple compliance checks, multiple points of contact when something goes wrong.

Sapphire supports umbrella, PEO, CIS and limited company accounting under one roof. Nine consecutive years of FCSA accreditation, SafeRec real-time auditing and self-billing capability apply consistently across all models. 

Sapphire processes more than 10,000 contractor payments per week and works with over 500 recruitment agencies, which means the team has handled the full range of placement types and edge cases you’re likely to encounter.

For agencies with a mixed contractor population – employed temps and self-employed subcontractors in construction, for example, having a single partner that can apply the right model to each placement type, rather than routing every placement through whichever model is most familiar, removes administrative complexity and compliance risk at the same time.

Sapphire’s contractor services team will assess the appropriate engagement model for each placement type, so you don’t have to carry that decision alone.

Getting it right from the start

Getting the engagement model right protects the agency, the contractor and the end client. The risks of getting it wrong are not theoretical: employment status misclassification can result in HMRC raising a PAYE liability with penalties and interest attached. Using CIS where umbrella is required exposes the agency to enforcement action. Using umbrella for a worker who should be engaged through PEO carries lower risk, but it creates the kind of contractor friction that affects your reputation and retention.

If a placement does not fit cleanly into one model, speak to a specialist before making a decision. That conversation is faster and cheaper than correcting a compliance failure after the fact.

Speak to Sapphire’s contractor services team about choosing the right engagement model for your placements. Contact Sapphire

Sapphire is an employee-owned operations partner for the recruitment industry. Sapphire holds nine consecutive years of FCSA accreditation and SafeRec real-time payroll auditing accreditation, and supports more than 500 recruitment agencies across umbrella, PEO, CIS and limited company engagement models.