For most UK agencies and consultants there's no VAT and no US tax to worry about — but SaaS is a different story. Get a straight answer for your business before you send that first invoice.
It usually happens like this. A UK agency lands its first proper US client — a New York brand, a California tech firm — the contract's signed, the kick-off call went well, and then the founder freezes at the invoice stage. Do I add 20% VAT? Have I just become liable for tax in America? Do I need to register for something over there? Cue a frantic Friday-afternoon Google and a few half-answers that contradict each other.
Here's the reassuring headline: for the vast majority of UK agencies and consultants, selling services to a US business means no UK VAT and no US income tax. The paperwork is lighter than you fear. The one group that genuinely needs to pay attention is SaaS businesses, where US state sales tax can creep up on you — and that's the part most people miss.
This article walks through exactly what applies to your situation, in plain English. It sits within our wider guide to how digital service businesses scale globally, so start there if you want the full cross-border picture first. Note we're talking about services here — not physical goods, which bring import VAT and customs into play and are a different topic entirely.