Yeah N.I is paid through your self assessment.
When you come to complete your self assessment you will need to also enter your employment income (P60)
You will pay tax on the profit over 11,500, including your employed income.
It?s best to keep a log of what you?re earning self employed and employed so that you can estimate your tax bill
Because you are also employed, if you do owe tax/NI you have the choice to pay this via your tax code. Meaning they will deduct it from your employment payslip
Or you can just pay it separately
Depending on how much you?re earning from escorting / how much profit you will be making, you?ll want to save some back so you don?t get a nasty shock.
It?s also good to note that if you have to pay over 1,000 tax, you then have to pay 50% on top in Jan and another 50% in July as a payment on acccount. Meaning if your bill is 1,000 you will pay 1,500 in Jan and 500 in July