If they live in France, Spain, Italy, or the USA, we recommend that they are not appointed as trustees, but they can be beneficiaries. This is because these countries do not recognise trusts, and they will tax the trustees as if they own the assets, which is something you would want to avoid.
In most cases, if your children live in one country and intend to move to another, it’s sensible not to have those children as trustees.
Another thing that has an impact is the type of trust that’s set up and that also plays a role in the decision if your children should be trustees or beneficiaries only.
One way of getting around this is in the Expression of Wishes letter which provides very strong guidance to your trustees. It can be used to enable people to get benefits after you die even if those people are not explicitly named as beneficiaries within the trust. If this is the case, you would want to appoint professional trustees on the death of the second spouse if the trust is set up by a married couple.
As always with Trusts, ensure you get experienced advice.