US / UK citizen living in UK and starting to work in US (mainly California)

Hello,

I am a UK / US citizen.  I have a small partnership in the UK.  I am starting to work in the US and am a little lost on how I should efficiently & legally get paid to work there.

I am taking on US clients.  Should I be doing this a sole proprietor? I don't want to set up a company in the US until I need to.   Are there limits as to how much I earn in the US and the number of days I can work there?

Are there other questions I should be asking?

Thanks for any help you can give.

Is the partnership is a controlled foreign partnership? Have you filed Form 8865? Assuming so, the Partnership will give you K-1s allocating income between US and foreign source.  If the Partnership is doing business in California, you'll also generate California K-1s and have a California liability.  You'll get a credit personally in the UK for any Federal & California tax. Hopefully you already have a certificate of coverage.

Ultimately you'll pay the higher of UK tax - or Federal + California tax (plus UK NIC) on your share of partnership profits.

It's not clear where you'll be living. If you are living and working in the UK and just taking on US clients then you'd just bill them and you wouldn't set up as a US sole proprietor.

Do bear in mind that unless it has made a check the box election that an English LLP is not a partnership for US tax purposes; although it is treated as one for UK purposes. Is the partnership to which you refer an LLP? If so, how is treated for US tax purposes?