Nanny - two employers and tax

[Iggly]

Can someone help?

We're reducing our nanny's days so she has found a new job. She'll do 2 days for us and 3 days for another family.

Can anyone help with the tax implications? We're registered with HMRC already and pay NI etc. However I'm a bit confused as to how it should change now that she'll have another employer - do we tell HMRC? Do we just tell the payroll agency what her new salary is (we've agreed gross) and not worry what happens with the other employer?

In my head the risk is that her salary will get taxed incorrectly and we'll end up under paying (or over) and get hit later on

More info here About multiple employers tax code but what does it say in her contract about whether you share the tax code etc?

You have agreed a gross salary so its easy. All you do is tell the payroll company the new salary and hours.
Once your nanny starts their new job, they complete a P46 saying it's not their only employment, and you may get a tax coding notice. Makes no difference to you what their taxcode is, as you have agreed Gross salary.

Thank you. Nothing about sharing a tax code.
Ok will let the payroll guys know - much easier than I thought.