Do I need to register with IRS if writing for US Website?

[flamingcarrot]

Hi - I am self employed, and am a UK citizen, also resident in the UK. In the last week, I have gained some freelance writing work for an American website, based in San Francisco. They will be paying me monthly, via Paypal, for my work. I plan to withdraw this money from Paypal, in GBP, and will register it with HMRC on my self assessment form.

My question is - do I also need to contact the IRS, and register in the US for tax purposes? I will not be travelling to the US, or doing any work on US soil. I have contacted HMRC, and they did not think I needed to register over there, but were not 100% sure. I am having great difficulty finding a definitive answer online, including on the IRS website.

If anyone could help out, or offer some advice on where to look, I would really appreciate it. Thanks.

[pqtaxation]

No need to inform IRS.

You are not performing services within US or have any establishment there.

Your profits are fully taxable in UK as you realise

[flamingcarrot]

Thank you - that is what I was hoping was the case.