Is tax always charged when selling a small property abroad (not BTL)?

[CatAndHisKit]

Can anyone advise please, what happens if you sell a flat abroad that used to belong to a parent and then ownership got transferred to the child who lives in the UK, while the parent continued living there 9rent free)?
The tax is definitetly payable in the country in question, and quiite high (20%) so would be crippling paying tax in the UK as well, it's a low value flat. It's never been let out, so not a source of income. And as the child never bought the flat, no capital gains as such (or at least how would it be calculated if seen as that).

In the UK if a property is gifted to a child by a parent the parent would pay CGT based on the market value at that time they gift it to the child.

Yes capital gains will be due on the difference between the sales price and the value at transfer to them

Depending on the second country, you should get a tax credit in the UK for the overseas tax already paid, also, assuming no other capital gains in the year, you would get an annual capital gains tax allowance in the UK