Your first US employee feels like a milestone. For most UK companies expanding across the Atlantic, it’s actually the moment a half-dozen consequential decisions get made wrong — quietly, expensively, and without anyone realizing until the bill arrives months later.
These decisions look administrative. They aren’t. They shape your compliance exposure, your benefits costs, your ability to attract American talent, and how quickly your US operation contributes to revenue rather than burns runway.
In 20 years of helping international companies build US workforces, we’ve watched the same five mistakes show up over and over. Here are the ones that cost UK companies the most.
Mistake 1: Choosing the Wrong Employment Vehicle
UK founders default to whatever employment vehicle the loudest voice in the room happens to be selling. EOR providers sell EOR. Immigration lawyers sell US entity setup. PEOs sell PEO. None are wrong, exactly — but their advice is shaped by what they offer, not by what your business needs.
The most common version is selecting a PEO for convenience. It’s the easy button — one provider handles payroll, benefits, and compliance. The problem is that PEO models are inherently cookie-cutter: standardized benefits, master health plans, and a customer-service model built for volume, not for the white-glove handling that sophisticated employers and employees expect.
We recently took a UK finance firm through a PEO extraction. They had launched in New York with about 75 employees on a PEO and expanded to remote workers across roughly a dozen states. Once they crossed that threshold, the PEO couldn’t keep up — neither on the operational sophistication required for multi-state payroll nor on the service standard a UK finance firm rightly demands. We extracted them and stood up a customized HRIS environment handling their HR, payroll, benefits, and compliance end to end.
The right question isn’t “which vehicle is cheapest?” It’s “can this vehicle support the company we are actually building?”
Mistake 2: Treating At-Will Employment as a Free Pass
UK founders often hear “at-will” and conclude that US employment is the Wild West — fire anyone, anytime, no consequences. The conclusion is wrong, and the cost of believing it is significant.
At-will is heavily constrained by federal protected-class law, retaliation claims, public-policy exceptions, and an expanding layer of state and city-level employee protections in places like California, New York, Massachusetts, and Illinois. None of that disappears because your offer letter says “at-will.”
The expensive lesson is that wrongful-termination claims aren’t usually won or lost on whether the termination was justified. They’re won or lost on whether the documentation supports it. UK managers used to indirect feedback and informal performance conversations create exposure long before any termination — they just don’t realize they’re doing it.
What changes when you cross the Atlantic: written warnings become standard. Performance improvement plans become standard. A documented paper trail becomes the difference between a clean exit and a five-figure settlement. The discipline isn’t about being more punitive. It’s about being more legible.
Mistake 3: Underestimating the 50-State Problem
Managing compliance in the US can feel like working in multiple countries simultaneously, particularly in highly regulated states like New York and California. UK employment law is one national framework. US employment law is a federal floor, fifty distinct state regimes built on top of it, and in some cases a city-level layer on top of that.
The states where this surprises UK founders the most are also the ones they’re most likely to hire in first: California, New York, Colorado, Massachusetts, Washington, Illinois. Each comes with its own minimum wage rules, overtime thresholds, paid leave programs, pay transparency requirements, final paycheck timing, and non-compete restrictions. None of these jurisdictions designed their employment laws to work together.
Remote-first hiring multiplies the problem rather than simplifying it. The moment you hire one employee in Colorado, your business has Colorado employment law obligations — full stop. By the time a UK company has remote workers in eight states, they’re effectively operating eight payroll-and-compliance jurisdictions, often without the outsourced HR infrastructure to keep up.
And in cities like New York City, San Francisco, and Seattle, a further set of local rules — pay range disclosure, sick leave, fair scheduling — applies on top of state law.
Mistake 4: Offering a UK-Style Benefits Package
UK companies arrive in the US carrying NHS-shaped assumptions about benefits. Health insurance is treated as a nice-to-have. Generous holiday is positioned as the main perk. The 401(k) match is described as optional flexibility rather than core compensation.
American employees at a 25- to 100-person company don’t see it that way. Quality health coverage with a low deductible and broad provider network is table-stakes. So is dental and vision. So is a 401(k) match — typically three to six percent. PTO that accrues in line with US norms, not UK ones. Parental leave that signals the company actually wants parents on the team. Increasingly, mental health benefits that go beyond a generic EAP.
A UK-flavored benefits package doesn’t just look weak compared to what candidates at this stage expect. It signals something more damaging — that the company doesn’t fully understand what it’s signing up for in the US, and doesn’t treat its US team the way it treats its UK one.
The cost shows up two ways: candidates politely declining offers, and the ones who accept churning out within twelve to eighteen months. Neither shows up clearly in a recruiting dashboard until it’s been happening for a year.
Mistake 5: Hiring the Role That Worked at Home
UK founders building a US presence usually default to hiring a senior salesperson or business development lead first. That’s the playbook that worked in the UK — get a strong commercial hire on the ground, give them a quota, watch revenue grow.
In the US market, that hire often fails — not because the salesperson is wrong, but because the foundation isn’t there to support them. They land into a company with no US-savvy operator handling state-level compliance, no marketing presence in US channels, and no customer success function to retain the customers they sign. Twelve months in, the structural problem is finally visible, but a year of runway has been spent.
The right question isn’t “who can sell in the US?” It’s “who can build the conditions under which selling in the US works?” For some UK companies that’s a US operator with cross-functional sophistication. For others it’s a marketing leader who understands the channels American buyers actually use. Whoever it is, they’re rarely the person who looks most like the first hire that worked at home.
Don’t Make These Five Decisions by Default
Each of these mistakes is small at the moment it’s made. They compound. By the time a UK company has a dozen US employees, a thin benefits package, an undocumented termination, a PEO that can’t handle multi-state complexity, and a salesperson who can’t sell because the foundation isn’t there — the cost isn’t a line item. It’s a year of momentum.
With 20 years of experience helping international companies build US operations — from first hire through multi-state scale — Kona HR has been in the trenches on every one of these decisions. If you’re a UK company planning your first US hire in the next six months, the time to get these decisions right is before you make them.
If you want to talk through your specific situation: Schedule a UK-to-US strategy call with Kona HR
