Is US tax refund taxable?

My previous employer from years ago was a US company (and I was based in the US). Last year I became UK non-dom tax resident. And last week I received a tax refund from IRS. I would expect that this tax refund would not be taxable in the UK as it concerns my employment long before I arrived to the UK. What’s HMRC guidance/view on this?

Hi

The tax refund from the IRS is not taxable in the UK.  HMRC does not tax, tax.

Thank you