US LLC vs UK sole trader for founders

A US LLC and a UK sole trader sit at opposite ends of the same question: how much structure does your business actually need? An LLC is a separate legal entity that shields your personal assets, signals permanence, and costs you filings and fees. A sole trader is just you, trading under your own name, with no separation, no entity, and almost no admin. They’re built for different founders, and comparing them side by side is the fastest way to see which one is you.

Pick the US LLC if liability protection, US customers, or a “real company” look matter to your business. Pick the sole trader route if you’re a UK-based solo founder testing an idea, keeping costs near zero, and your work doesn’t expose you to much risk. The rest of this post is the detail behind that verdict.

The honest comparison

These aren’t the same kind of thing, which is the point. One is a company; one is a status you hold as an individual.

Liability — the real dividing line

This is the difference that matters most, and it’s binary.

A US LLC is a separate legal person. The business owns its contracts, debts, and risks; you own the LLC. If the company is sued or can’t pay a supplier, claimants generally go after the company’s assets, not your house or savings. That shield is the entire reason the LLC exists — and it holds only while the company is properly maintained and in good standing.

A UK sole trader has no shield at all. There is no separate entity — legally, the business is you. Every debt the business takes on is your personal debt. If a client sues, your personal assets are on the line. For a low-risk service business (writing, design, consulting where mistakes are cheap to fix) that exposure may be perfectly acceptable. For anything where a single bad outcome could be ruinous — you hold client money, sell a product that can cause harm, sign large contracts — the lack of separation is a real problem, and it’s the clearest signal to incorporate instead.

Tax treatment

Both keep tax relatively simple, but in different ways.

A UK sole trader is the simplest tax setup there is. You register with HMRC, report your business profit on a Self Assessment return once a year, and pay income tax and National Insurance on that profit as part of your personal income. There’s no separate business tax return and no corporation tax. Your profit is just your income.

A US LLC is, by default, pass-through — a single-member LLC is a disregarded entity, so the company doesn’t pay its own federal income tax and the profit is treated as the owner’s. For a non-resident with no US-effectively-connected income, that can mean little or no US federal income tax, but the filing obligation remains: a foreign-owned single-member LLC must file Form 5472 with a pro-forma 1120 every year, and the penalty for missing it starts at $25,000. And if you’re a UK resident owning the LLC, you still report the income on your UK Self Assessment — the LLC doesn’t make UK tax disappear. The mechanics for non-residents are in the US LLC tax guide.

Cost and admin

The sole trader wins on pure simplicity, and it isn’t close. Registering with HMRC is free, there’s no entity to maintain, no annual report, no registered agent, no franchise tax — just keep records and file one Self Assessment a year. For someone testing whether an idea even earns money, that near-zero overhead is exactly right.

A US LLC carries real running costs: a state formation fee, an annual registered agent, annual report filings, possibly franchise tax (California’s $800 is the notorious one), and the yearly Form 5472 preparation. None of it is huge individually, but together it’s a few hundred dollars and several deadlines a year. You’re buying the liability shield and the credibility with that money — make sure you actually need them. The full breakdown is in how much a US LLC costs.

Credibility, customers, and getting paid

How your business reads to others can tip the decision.

A US LLC looks like a company because it is one. US B2B customers are comfortable contracting with an LLC, it carries an EIN for invoices and W-9s, and it gives you access to Stripe US with USD payouts — useful if your customers are American. For founders selling into the US market, that “established business” signal removes friction.

A sole trader can absolutely take payments — many use Stripe UK without issue, invoice clients, and run a perfectly real business. But larger clients, some marketplaces, and certain platforms prefer dealing with a registered company, and trading under your own personal name can read as less permanent. If your buyers are individuals or small UK businesses, this rarely matters. If you’re chasing enterprise contracts, it starts to.

So which fits you?

Be a UK sole trader if you’re a UK-based solo founder, your work is low-risk, you want to start for free with minimal admin, and you’re still proving the idea earns. It’s the right amount of structure for most people at the very beginning.

Form a US LLC if you need the liability shield, your customers are American or expect a registered company, you want USD payouts through Stripe US, and you’re past the testing phase into something worth protecting. Start with forming a US LLC as a non-resident.

And if you’re weighing a US LLC against a UK limited company rather than sole-trader status — a closer comparison — read UK Ltd vs US LLC next. The honest summary here: a sole trader and an LLC aren’t competitors so much as different chapters. Plenty of founders start as a sole trader and incorporate once the risk, revenue, or customers justify it.