Declaring payment from a US company

Hello, In the last tax year (2022-2023) an American company sent me money for some online documentation that I wrote. They paid me in pounds (GBP) . I am British, in the UK, with a UK bank account. I'm wondering if/where I should declare that on a self assessment form (my tax owed will be £0 either way so this makes no difference to the calculation)? Looking at fhe form online it says: "If I received foreign income, do I need to complete the foreign section". 1) Is this considered foreign income? It is money from a foreign company ... however it was paid in GBP to my UK account, and it doesn't seem to match any of the listed examples for which the form says you should tick 'yes' (e.g "interest and income from overseas savings", "dividends over £2000 from foreign companies" ... and so on). 2) If it _is_ considered foreign income, "do I need to complete the foreign section"? I won't have to pay any tax on it, and am not claiming any allowances, relief, expenses ... etc. 3) If no to (1) or (2) ... do I need to declare that payment somewhere _else_ on the form? I see there is an "Other taxable income" Box 17, perhaps. Or not. Thank you.

Hi Greg,
As you are not employed by this company, the payment you have recieved would be considered a royalty, which falls under self employment.  
You should complete SA103S, to declare the payment.  
You can also claim up to £1000.00 business income allowance, if you are not claiming any expenses.  
You do not need to complete the foreign section, if you declare the royalty in SA103S, unless you paid tax in the overseas country and wish to claim a tax credit.
Self Assessment: self-employment (short) (SA103S).
Thank you.