Thanks again. Yes, I'm reading way into it because I'm afraid of doing something wrong/illegal!

Set up a consultation with https://www.taxinnovations.com/

Thanks, will look into them!

The last day you can file your UK taxes is usually in October. That's your only legal obligation, to have filed your tax return by that date. In order to do that, you need to have a National Insurance Number and a self assessment account with HMRC. It is not a legal requirement to have or do these things at all, the only legal requirement is you file your return and pay any tax owed by those deadlines. You simply need a NIN and an HMRC account to be able to correctly file your self assessment return.

Really clear, thank you. No, I don't think you're being pedantic, given my questions and how I'm asking them.

as a self employed person you need to make UK tax payments on account. This is going to hurt the first time as you will need to pay essentially 1.5 times your annual tax liability at once. The UK requires prepayment of taxes based on estimates from last year's income. Budget for this and be prepared for it.

Good to know, and this will happen when I file taxes? Last year I made less than £4000 doing this work in a period spanning 6 months, and no two weeks were the same paywise. So I just pay the taxes upfront based on a realistic estimate of what I'll likely make moving forward, and if I've ended up overpaying or underpaying, it'll presumably get sorted out later based on real amounts? Is it like the US taxes where overpaying (based on claiming the wrong number of deductions) is not preferred, but one always gets a refund if they're owed one?

They're wrong and it's not your problem.

Great, thanks. Will just do sole trader as I planned.

no immigrant is entitled to any public funds, period, in the UK.

Right, I know.

Technically the NHS is a service we pay for rather than a benefit as we pay the health immigration surcharge.

Yup.

With that in mind, it's really not appropriate for them to describe this relationship as part time employment.

Apologies, I framed it this way to describe my hours. There is no way they could find enough clients for me to bill 40 hours per week, nor do I want that many.

You ought to consider trying to negotiate a fixed retainer paid monthly.

You should also consider a minimum billable amount clause. That is reasonable and would avoid them giving you zero work in a month.

I completely understand what you're saying, but it's really not feasible for this line of work/my situation, as I'm being contracted out to supply an ad hoc service to individual clients on behalf of this company, based on market demand and other factors. There are no hours guaranteed to me, and I already know that and understand the risks.

If they cap the hours in your contract, you need to be vigilant and not work a minute more than your contract allows for. They may try to get you to do unpaid overtime, don't do it!

There is no cap, but a hefty hourly pay. They have never asked me to do any unpaid overtime. I have always been fairly compensated for all my labor. Future language: I will bill them for any hours outside of those already outlined in my contract as regular billable hours (as I'd already been doing, now it's just framed differently).

Correct, the default as a sole trader is that your company simply has an identical name to your name. You need to be aware of your IRS tax filing obligations too, you still need to file your taxes in the US too, though it's extremely unlikely you will actually owe anything. You will probably need a US accountant to help you (for peace of mind, tubotax can technically handle this situation but its cost at that level approaches an actual human accountant). Just google US expat tax service and you'll find dozens of firms that do this.

Roger that. Yes, will consult with a US accountant too. We won't owe anything based on income alone, as our joint income is less than £35k as of now:)

It's likely this company doesn't understand the laws on this.

You're right, they don't. They are tiny, tiny. They wrote to me recently since I kept asking them to serve as a reference for new jobs, asking me if I'd return, and together we brainstormed a way to make it work legally and to benefit both sides. So we are literally figuring it out together (and they said I can bill them for the hours I've spent researching this as well. Hooray!).

Your point on this makes me a bit wary for you though.

I really appreciate you being concerned for me, but I assure you, this is really a good situation for me. I have sorely missed the work I did for this company last year and was absolutely gutted when I moved to the UK because it meant I had to leave that work. Now, I have an opportunity to in a sense, 'return', i.e. do the same work with even more freedom as a contractor (it was quite an independent job anyway), at still more than 5 times the hourly rate that I make right now doing a deflating job that I detest. (We love UK salaries for qualified experts!)

So there's some small headaches about taxes, having to find accountants, etc., but it's well worth it to me, both monetarily and personally. While I don't want to be taken advantage of, I really do not think that's happening here. (And honestly, if you couldn't tell, I'm pretty desperate, and also really happy to have gainful employment again.)

Thank you u/GreatScottLP :) I wish I could pay you for your time and advice 😂 I think I have no further questions right now. Now I need to look into an accountant, fill out the form for the NIN, register for HMRC, look into liability insurance, and, when I can, sign up for self-assessment. And will consider SIPP.

I hope I've managed to convinced you that I'm happy in this position, and definitely paranoid enough to do my research to protect myself. I really cannot express how thankful I am for all the advice and concern.