What is a PEO? Definition, pros, cons and costs for growing companies

Published Thursday 2 July 2026

Table of contents

• What is a PEO?
• How a PEO works in co-employment
• Pros and cons of a PEO
• What does a PEO cost?
• PEO vs EOR: what's the difference?
• Ready to simplify payroll and HR with Xero
• FAQs on PEOs

Key takeaways

• A professional employer organisation (PEO) provides outsourced HR and payroll services through a co-employment agreement, where responsibility and liability for certain tasks is shared between you and the PEO.
• PEO services typically include payroll management, benefits and compensation packages, and consultancy on employment law, employee contracts and compliance.
• While a PEO can save your business time on HR and payroll admin and take on some compliance liability, it's important to weigh up the risks. Choose a PEO with experience in your location and industry, and make sure payroll runs smoothly for your staff.
• PEO costs vary by provider and usually increase as you add more employees. Common pricing models include a per-employee monthly fee, a percentage of payroll or a flat monthly rate.

What is a PEO?

A professional employer organisation (PEO) is a company that provides outsourced HR and payroll services for businesses through a co-employment arrangement. Under this model, the PEO shares certain employer responsibilities with you, handling tasks like payroll processing, employee benefits administration and employment law compliance, while you keep full control of day-to-day operations and your workforce.

PEOs typically offer a software platform or system for managing HR, alongside human expertise to carry out tasks compliantly. The services on offer can be far-reaching, covering payroll, employee benefits, risk management, and employment and tax compliance.

The difference between a PEO and a typical outsourced payroll or HR provider is the working model. When you start working with a PEO, you enter into a co-employment agreement. This makes the PEO a co-employer for certain aspects of HR, while you maintain overall control of business operations.

PEO services are well established in the US. In the UK, more providers are entering the market, and they tend to be international software companies that can support global expansion. Many PEOs have expertise across multiple jurisdictions, helping businesses meet HR and payroll obligations overseas. PEOs also give smaller businesses and startups access to HR expertise without the need to hire an in-house team.

How a PEO works in co-employment

When you work with a PEO, the PEO becomes a co-employer. This means the PEO takes responsibility and has some liability for the HR and payroll services it provides, while you maintain responsibility for employing staff and managing employees day to day. Liability and responsibility is set out in a contract between you and the PEO.

For example, a PEO hired to handle payroll would be responsible for:

• Paying employees the correct amount every pay run
• Calculating the right deductions and forwarding these to HMRC
• Making sure your staff receive statutory pay and employment benefits when they're entitled to them
• Keeping complete and accurate payroll records
• Communicating with your employees about payslip queries, benefits and tax where agreed

The PEO would also be liable for compliance with payroll and employment laws when carrying out these tasks, though as a co-employer, this liability is shared with you.

While the PEO takes on some responsibility, it's still up to you who you hire, the rate of pay, and whether an employment contract is extended or ended.

What PEO services include and exclude

You can expect a PEO to offer the following types of services:

• Payroll management, including processing employee pay and deductions, preparing submissions to HMRC or overseas agents, handling expenses and keeping records
• Providing benefits and compensation such as private health insurance and pensions
• Creating employment contracts, employee handbooks and workplace policies
• Consultancy on local employment, tax and HR law compliance, including UK obligations under the Employment Rights Act 1996, GDPR and Making Tax Digital (MTD) for VAT

Whatever services you use from a PEO, it's important to have a clear contract in place that sets out roles and responsibilities. Since you'll be sharing liability with the PEO as a co-employer, all parties need to be clear on what they're responsible for.

While a few PEO companies offer hiring services, recruitment usually remains the employer's responsibility. Organisations that offer the same services as a PEO but also employ people on behalf of a business are known as employers of record (EORs).

When to use a PEO

PEO HR and payroll services make sense for all kinds of businesses.

A startup could benefit from working with a PEO in its early stages, when it doesn't have the budget to hire an in-house HR and payroll team. This gives access to specialised HR and payroll services and helps meet employment and tax obligations, without adding employed staff to the wage bill. A PEO could also advise on contracts, hiring strategy and ongoing compliance with UK laws, including HMRC reporting, GDPR requirements and auto-enrolment pension obligations, as the business grows.

Larger businesses looking to expand internationally can also benefit from PEO services. For example, a UK-based company planning to expand into the US could choose a PEO instead of hiring a local HR team. This means the business can still meet employment and payroll obligations by using a PEO with local expertise, without adding full-time HR staff in the new location.

Pros and cons of a PEO

A PEO has the potential to free up your business and create more room for growth. But it's not a decision to take lightly, since you'll be handing over key responsibilities that affect your staff. Consider the benefits and drawbacks before settling on this option.

Pros

A PEO can bring several benefits to your business:

• Gain access to expertise outside of your business. PEOs are made up of HR and employment law experts who can offer knowledge you might not have internally. Using a PEO for HR and payroll tasks means you can still meet compliance obligations without an in-house team.
• Reduce your admin and focus on what counts. With a PEO taking care of HR and payroll tasks, you can focus on what matters most to your staff: fostering a great working environment, making space for collaboration and helping your team develop.
• Save on employee benefits packages. PEOs work for multiple businesses, giving them additional bargaining power when securing benefits and private insurance for their clients.
• Handle global employment and HR obligations. International PEOs can manage HR and payroll across multiple jurisdictions. This makes expansion into new locations easier for businesses without specific regional expertise. According to the National Association of Professional Employer Organizations (NAPEO), small businesses that use PEOs grow seven to nine per cent faster than those that don't.

Cons

There are also some drawbacks to consider:

• Increased friction for employees: In some cases, your staff may find it frustrating if they have to go through a third party to resolve pay issues or query employment benefits. Delegating work to a PEO could make it harder for employees to get support.
• Shared liability, more risk: Since the PEO is a co-employer, it has responsibilities and liability for the HR and payroll tasks you assign it. It's important to pick a PEO with expertise in your industry and the location where you're hiring, so it can meet compliance standards.
• Increased costs as your business grows: While initial savings may come through using a PEO instead of hiring in-house, as your staff numbers grow, the price of outsourced services tends to rise too.

What does a PEO cost?

PEO pricing varies depending on the provider, the services you select and the size of your workforce. Most PEOs use one of three pricing models:

• Per-employee monthly fee: You pay a fixed amount for each employee on your payroll. This is the most common model and makes costs predictable as you scale.
• Percentage of payroll: The PEO charges a percentage of your total payroll spend, typically between two per cent and 12%. This model means costs rise in line with wages, bonuses and overtime.
• Flat monthly rate: Some providers offer a single monthly fee regardless of headcount, though this is less common and usually suits smaller teams.

Several factors affect what you'll pay. The number of employees on your payroll is the biggest driver, but the range of services you need, the complexity of your industry and whether you operate across multiple jurisdictions all play a part. Some PEOs also charge a one-off setup fee when you first sign on.

It's worth comparing quotes from several providers and checking exactly what's included. Ask whether payroll processing, benefits administration and compliance consultancy are bundled or charged separately, so you can weigh the total cost against hiring an in-house HR team.

PEO vs EOR: What's the difference?

PEOs and employers of record (EORs) both help businesses manage HR and payroll, but they work in fundamentally different ways.

With a PEO, you enter into a co-employment arrangement. You remain the legal employer of your staff, while the PEO handles specific administrative tasks like payroll, benefits and compliance. Responsibility is shared between you and the PEO under a contract.

An EOR, by contrast, becomes the legal employer of your workers in a given country. The EOR takes on full responsibility for employment contracts, tax filings and labour law compliance. You still manage the employee's day-to-day work, but the EOR holds the legal employment relationship.

A PEO suits businesses that already have a legal entity in the country where they're hiring and want to outsource HR admin. An EOR is better when you need to hire in a country where you don't have a registered business, since the EOR can employ staff on your behalf without you needing to set up a local entity. In the UK, this distinction matters for HMRC payroll obligations and compliance with the Employment Rights Act 1996.

Simplify payroll and HR with Xero

Taking care of HR and payroll requires attention to detail, employment law expertise and plenty of admin. That's why it makes sense for some businesses to outsource these functions to a PEO.

But there are other steps towards simplifying HR and payroll, like using Xero software. With Xero, payroll processes are fast and automated. Employee pay and deductions are calculated for you, and HMRC real-time information (RTI) submissions are sent automatically after every pay run. So you can be confident you're meeting UK payroll compliance requirements.

Xero also offers time tracking software that makes it easier to monitor who's working and how much they need to be paid. Plus, with the employee self-serve app, Xero Me, your staff can make leave requests, check holiday entitlements and view their payslips from their smartphone.

Xero also integrates with a range of HR platforms including HiBob, Remote and Deel, so you can bring your accounting and HR information into one clear view.

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FAQs on PEOs

Here are answers to common questions about professional employer organisations and how they work.

Who's the employer in a PEO arrangement?

You remain the employer of your staff. The PEO acts as a co-employer, sharing responsibility for specific administrative tasks like payroll and HR compliance. You keep full control over hiring, management and business operations.

How much does a PEO cost per employee?

Most PEOs charge a per-employee monthly fee, which can range widely depending on the provider and the services included. Some providers use a percentage-of-payroll model instead, typically between two per cent and 12%. It's best to request quotes from several providers to compare.

What are the risks of using a PEO?

The main risks include shared liability for compliance errors, potential friction for employees dealing with a third party for pay and benefits queries, and rising costs as your team grows. Choosing a PEO with proven expertise in your industry and location helps reduce these risks.

Is a PEO the same as an EOR in the UK?

No. A PEO shares employer responsibilities with you through a co-employment agreement, but you stay the legal employer. An EOR becomes the legal employer of your workers, taking on full responsibility for contracts, tax and compliance. An EOR is typically used when you don't have a legal entity in the country where you're hiring.

What should you look for in a PEO?

If you're using a PEO in the UK, make sure it has strong knowledge of UK employment law, HMRC payroll obligations and GDPR. Check for case studies from businesses similar to yours, and confirm it can handle compliance across any other jurisdictions where you operate.