Payroll, PEOs, and EORs: The Modern Employment Stack

Payroll is the single workflow that, when it breaks, breaks trust faster than any other HR system. Modern teams have three architectural choices: run payroll yourselves with a vendor, outsource employment to a PEO, or use an EOR for countries where you don’t have an entity. The choice depends on geography, headcount, and how much HR muscle you have.

What payroll really does

Payroll is more than ‘send money on the 25th’. A payroll system calculates gross-to-net (taxes, social contributions, pre- and post-tax deductions), files statutory returns, issues payslips, manages year-end tax forms (W-2 in the US, P60 in the UK, equivalent forms elsewhere), handles garnishments and child support, supports multi-state or multi-country complexity, integrates with your HRIS and accounting system, and produces an audit trail.

The payroll-HRIS handshake

Employee data should originate in the HRIS and flow to payroll, never the other way around. If your payroll vendor is also your HRIS (Gusto, Rippling, Justworks), that handshake is internal. If they’re separate, you need a tested sync and a named owner.

Gross-to-net, step by step

How a paycheck is calculated

1
Gross earnings
Base salary + variable + overtime + reimbursements.
2
Pre-tax deductions
401(k), pension, salary-sacrifice, certain benefits — reduce taxable income.
3
Statutory taxes
Federal/state/local income tax + employee social contributions (FICA in the US, NI in the UK, etc.).
4
Post-tax deductions
Roth 401(k), garnishments, post-tax benefits, voluntary deductions.
5
Net pay
What hits the employee’s bank — typically within 1–3 business days of run.
6
Employer-side costs
Employer payroll taxes, employer pension match, benefits premiums — invisible to the payslip, very visible to your finance model.

Fully-loaded cost = salary × ~1.20–1.35 in the US, ~1.25–1.45 in much of Europe. Always model employer-side costs into your headcount plan.

Payroll, PEO, EOR — compared

Payroll vendor vs PEO vs EOR

PEO (co-employment)

Vendor is co-employer for tax/benefits/HR; you direct the work
US-focused (Justworks, TriNet, Insperity, Sequoia One, Rippling PEO)
Access to pooled benefits at better rates than small employers can get alone
You stay on payroll; you can switch to standalone payroll later (with effort)
Best for US SMBs 5–150 employees in one country

EOR (employer of record)

Vendor is the legal employer in a country where you have no entity
Global (Deel, Remote, Oyster, Velocity Global, Papaya)
Lets you hire in ~150 countries without incorporating
Markup is ~£400–800 / $500–1,000 per employee per month over salary
Best until you reach ~5–10 employees in a country — then incorporate

When to use which

Situation	Use	Why
US SMB, 1 country, <150 people	PEO	Benefits pooling + HR support beats DIY
US company, 150–500 people, 1 country	Standalone payroll (ADP, Gusto, Rippling)	Direct control, no co-employment markup
Hiring 1 person in Portugal, you’re US-only	EOR	Incorporating for one person is irrational
8+ people in Germany, growing	Local entity + local payroll	EOR markup exceeds entity cost
Truly global team, 10+ countries	Hybrid — entities where dense, EOR where sparse	Standard pattern for series B+
Independent contractors abroad	Contractor-of-record (Deel, Remote)	Manage IP, classification, payment FX

Misclassification is the killer risk

Calling a worker a ‘contractor’ when they function as an employee creates back taxes, social contributions, and penalties — often double-digit percent of cumulative pay. Many countries (UK, Germany, Spain, France, India) audit this aggressively. EOR is the safer default if you’re not sure.

Hiring globally without an entity

Decide if the role is genuinely remote-global or anchored in a country.
Run the math: EOR cost vs entity setup + local accountant + local payroll.
Check the country’s realities: notice periods, 13th month, mandatory benefits, IP assignment law.
Use an EOR until you have 5–10 people in a country, then transition.
Plan the transition path with the EOR before you sign — getting out is harder than getting in.

Vendor landscape

Directional only — verify pricing and country coverage

Vendor	Strength	Best for
Gusto	Modern SMB payroll + light HRIS	US SMBs <100
Rippling	Payroll + HRIS + IT in one	Tech-forward SMBs and global teams
ADP / Paychex	Enterprise depth, complex tax	Mid-market and enterprise US
Justworks / TriNet / Insperity	PEO + benefits + compliance	US co-employment model
Deel	EOR + contractor + global payroll	Global hiring, fast
Remote	EOR with strong IP / equity story	Global hiring with founders
Papaya Global	Global payroll aggregation	Larger global enterprises
Workday Payroll	Enterprise integrated with Workday HCM	Large enterprises already on Workday

Compliance pitfalls

Worker misclassification (employee vs contractor) — country-specific tests apply
Multi-state nexus: hiring one person in a new US state can trigger registration, unemployment insurance, and state tax filings
Mandatory benefits missed (13th-month pay in many countries, pension auto-enrolment in UK, congé payé in France, etc.)
Termination law: at-will is a US exception; most countries require notice + cause + documentation
Data-residency: payslip data is personal data under GDPR — know where it’s stored
Equity in EOR countries: stock options may not be tax-efficient or even enforceable — get local advice

References

IRS — Worker classification (US) — IRS
UK HMRC — IR35 / employment status — HMRC
ICP — Global employment guides — G-P
OECD — Taxing wages report — OECD
Deel — Global Hiring Guide

Written by Pawan Joshi. Sources cited inline. Last updated 2026-05-17.