Working out tax when self-employed and employed

[Writerinneed]

Boring tax question. I’m about to have two jobs, one self employed and one employed (so PAYE). I’m registered as a sole trader and have been self employed for years, so usually pay tax via self assessment. What will happen once I’m earning as both a sole trader and an an employee? Do I need to tell HMRC about this (and if so how? I’ve never been able to get through on the phone) or can I just assume that it will all become clear once tax is being deducted via PAYS from my employed job and I do an annual self assessment for my self employed job as usual? I’m quite worried about not paying enough tax and then being landed with a huge bill…

You also fill in your employed income on the self assessment plus the tax paid via PAYE, all the figures are on your P60 that you will receive annually as an employee.
The employed income is therefore declared, but as tax has been paid it doesn’t impact the calculation of tax owed…that ends up being just calculated based on the sole trader income amount.

don’t forget the tax calculation is for the previous year so you won’t need to declare it in this year’s calculation if you started being an employee after April 6th.

It asks you on the self assessment form if you have a paye job too and if so to fill in a bit of info about it. You’ll just have ticked no on that part in previous years :) it’s very easy don’t worry about it. And you’ll have been paying tax on it already so it’s all sorted.
I’ve done it before only takes an extra couple of minutes.

I used to be a sole-trader (window cleaner) and also received a pension which was taxed. When you fill out your self- assessment form in the income section there's space to put your PAYE income, along with tax paid.

All the various tax forms - for employment, self-employment, bank interest/dividends etc - can be found on the HMRC website. Have a look at them and all will be clear, particularly if you also read the separate notes for each section.

There is a lot of useful information on the .GOV website. If you are not yet registered with .GOV you should do so.