Any payroll experts around?

[Carameljack]

I’m hoping for a bit help. If I’m employed part time and start up a bit of a side hustle (think Etsy shop etc) in my spare time and sort my tax return out myself for this extra income, will my employer find out through the tax code or anything?
Nothing in my contract to not allow it, different industry, I’m not trying to poach clients or anything, just wondering if they would know I have another source of income?
Thanks

They will find out through your tax coding, through a P6/P9. You can speak to HMRC to offset your tax though. I’m not a payroll expert but I do work in payroll, we honestly don’t pay attention to the tax side we just process the P6/P9’s unless an employee has an issue with their tax we chat through it but can’t speak to HMRC on your behalf, if the at makes sense. I work for a large company it maybe different if it’s a small company. I hope that helps

Ok thanks.

You can earn up to £1,000 a year as a hobby trade without having to declare it. I'm not sure if that is £1,000 of turnover or profit but worth looking into.

Company may get a notification from HMRC to amend your tax code but it won't say why

Unless you specify that you want to collect your self employed income via your tax code it won't change. Your tax free allowance will remain in you employment, any left over allowance will be off set against your SE income. If there's none it will be a 20% tax charge on your net profit.

So if I just fill in a self assessment and pay the tax due on the self employed income then my tax code wouldn’t necessarily change?

That's right, you'll need to fill out the employment page of the SA return as well but both sources of income can be separated. Phone the self employed helpline to register and let them know you want your tax free allowance to remain with your employer.