Most contractors hear "PEO" and assume it's a dressed-up umbrella with a different name. It isn't.
The differences are structural, and on a contractor's actual take-home they show up in places that aren't obvious until you look closely.

Umbrella PAYE works like this. The umbrella employs the worker. The agency pays the umbrella an assignment rate. Out of that rate, the umbrella deducts employer's NI, apprenticeship levy, pension contributions, holiday pay, and their margin. What's left becomes the worker's gross pay, which then has employee PAYE and NIC deducted to produce the net.
The model is well-understood. Most contractors have used it. It works. But it does mean the worker is, in effect, paying the employer's costs out of their assignment rate — because the rate quoted to the agency is the all-in cost, not the worker's gross.
PEO is structurally different.

A Professional Employer Organisation employs the worker, but the cost structure is closer to direct employment. Employer's NI is paid on top of the gross pay rather than out of it. Holiday pay accrues separately. Pension contributions are employer-funded properly, not extracted from the worker's rate. The agency or end client pays the genuine all-in employment cost, and the worker gets a payslip that looks more like a permanent employee's than a contractor's.

For some workers, this changes the take-home calculation materially. For others, it changes very little. The honest answer is that it depends on the assignment rate, the agency's willingness to pay genuine employer costs on top, and what the worker actually values from the engagement.

Here's where the practical differences land.
Holiday pay under PEO is usually paid as a proper salary continuation when taken, not rolled up into the hourly rate or paid as a separate "holiday accrual" line. That sounds minor. It isn't. Rolled-up holiday pay was technically illegal for years before being clarified more recently, and many umbrella workers still receive it in ways that obscure how much they're actually owed. Under PEO, holiday is salary. Take a week off, get paid for the week. No reconciliation, no chasing.

Pension contributions under PEO are typically employer-funded at 3% minimum, with the employee adding their 5%, exactly as in permanent employment. Under umbrella, the technical legal position is the same but the funding mechanism often means the contractor is effectively paying both portions out of their own assignment rate.

Statutory pay — SSP, SMP, SPP — works the same way under both models legally. In practice, PEO providers tend to administer it with fewer disputes because the employment relationship is structured more clearly.
The big one: employment rights.

Both umbrella and PEO workers are employees of the umbrella or PEO, with the corresponding rights. But under PEO, the employment is usually treated more like permanent employment for the purposes of continuous service, redundancy entitlement, and unfair dismissal. For workers on long assignments — six months plus with the same end client — that distinction can become significant if the assignment ends in a way the worker disputes.

What PEO doesn't do is solve every problem. It's not cheaper than umbrella. The administration is heavier. Some agencies don't offer it, or won't pay the additional employer costs on top of the assignment rate. And for short, high-churn assignments, the umbrella model is still simpler and often makes more financial sense.
Where PEO makes sense is for longer-term assignments, higher-value contractors, and workers who want a payroll relationship that looks and behaves more like employment than contracting.

Where umbrella PAYE makes sense is shorter assignments, contractors who switch between agencies frequently, and workers who prioritise simplicity over the structural distinctions PEO introduces.
The mistake we see most often is contractors picking umbrella by default because that's what the agency offered, without ever being told PEO existed as an option. The reverse mistake — picking PEO when you'd be better off on umbrella — is rarer, because PEO is rarely the default.

If you're on a long assignment with a single end client, drawing a senior day rate, and the agency won't engage with PEO as a model, that's worth questioning. If you're switching projects every few weeks across multiple agencies, umbrella is probably still the right call.

We offer both. PCA-approved, fully compliant, with proper documentation behind every worker we payroll. If you want to know which model actually fits your circumstances, get in touch and we'll walk you through it honestly — including telling you when neither of them is right and you should be on direct PAYE with the end client.