⏱️Quick Win: How to set up your US company entity from the UK (a step-by-step guide)

Take the headache out of setting up your US entity with this one tool

Jul 03, 2025

Hey there,

If, like me, you’re a UK founder who also needs needs to focus on the US — whether to attract investors, find more customers, or expand your brand — one of the first questions is:

How do I actually set up a US entity?

I went through this a few years ago and know it can feel confusing, frustrating, and a little overwhelming (especially when you’re then dealing with taxes in more than one country).

Thankfully, I found Firstbase, a platform that made the entire process quick, simple, and totally online.

Here’s a detailed quick win for you: how to set up your US company using Firstbase, step-by-step, with everything you need to know.

P.S. Just so you know, this isn’t a sponsored post. I’m recommending Firstbase because I’ve used it, trust it and found them super helpful when it came to setting up my US entity.

Step 1: Understand your business entity options (and get advice)

The kind of company you form depends on your goals:

Seeking US investors? Most investors prefer Delaware C-Corporations because of their structure and investor-friendly rules.
Focusing on sales or services? An LLC might make more sense for flexibility and simpler tax treatment.

This choice affects taxes, liability, and paperwork, so I highly recommend consulting a legal or accounting professional to make sure you pick the right option for your business.

You’ll need to make a firm decision on this before you start using Firstbase, because it’s literally one of the first questions they ask you.

Step 2: Prep your information — here’s what you’ll need

Before you start your application, make sure you have the following ready to go:

Proof of your full legal name and date of birth
Proof of your current home address (can be in the UK)
A government-issued ID or passport for identity verification
The business name you want to register (have 2-3 options ready in case yours is taken)
A short description of your business activities (e.g., “e-commerce sales of beauty products”)
The US state where you want to incorporate — Delaware is popular for start-ups but you can pick other states too
Your company ownership structure: number of owners (members/shareholders) and their details. This means any existing investors, basically anyone who has equity.

Step 3: Start your application on Firstbase.io

The application process is pretty straightforward and should take you 10-15 minutes. Here’s what you’ll be running through:

Selecting your entity type (LLC, C-Corp, etc.) — remember to check with your advisor first
Entering your prepared info from Step 2
Choosing any additional services like:
- Registered Agent Service: Firstbase acts as your registered agent and provides a US business address for legal documents — important if you don’t have a US office. This service is a monthly fee (usually ~$30)
- Employer Identification Number (EIN): This is your US tax ID number — essential for banking, hiring, and taxes. Firstbase will apply for this on your behalf.

Step 4: Pay & Submit your application

The cost varies based on your entity and services but generally expect:

Incorporation fee: $300–$500
Monthly fees for registered agent and business address (if you opted for this)

Step 5: What happens next?

Firstbase files your paperwork with the state government — this can take a few weeks
You’ll receive official company formation documents (e.g., Certificate of Incorporation) via email
Your EIN (Employer Identification Number) will arrive electronically via the platform
With these documents, you can:
- Open a US business bank account (some banks allow remote opening) - Mercury is a good option.
- Register for US taxes and permits
- Legally operate your US company

Bonus tips from my experience:

Use the registered agent service if you don’t have a US address — it’s worth the monthly fee to stay compliant and avoid missing official mail.
Have your business name alternatives ready — sometimes your first choice isn’t available in the state you pick.
Make sure your business description is clear and professional — this helps avoid delays in approvals.
Keep digital copies of all your formation documents and EIN for future reference and applications.
Affordable accountant partners: The US tax system is blindingly complicated, so Firstbase can both do the tax filing for you or recommend some really affordable options.

Why this is a win for UK founders

Entirely online: No need for US trips or dealing with confusing government websites
Time-saving: From start to finish in under an hour to apply, with documents back in a few weeks
Confidence: You know everything is done correctly and legally, ready to start US operations or attract investors
Great customer support: They have an online chat for existing customers and their team are pretty helpful when it comes to explaining what needs to be done.

I hope you’ve all found this helpful! Finding Firstbase definitely made me feel like setting up a US company was doable, more straightforward and affordable than I originally thought (hopefully you feel the same way too).

Ciao for now,

— Jade

P.S. Have questions or want to hear about some of the challenges I faced? Just reply to this email — I’m happy to help.