I wonder just how the taxman would, or could, pursue the tax. Obviously they can’t summon you to appear before a UK court and, as Tilia points out, tax evasion is not a criminal offence in Switzerland. Could the UK authorities persue a civil case in a Swiss Court ? The USA could not pursue Marc Rich even though he was on the FBI’s most wanted list.

My father asked me to be sole beficiary and executor of his will in Australia. No thanks. I told him he should spend the money before he goes and the aggro with the family just isn't worth it.

Apparently they would:
http://www.hmrc.gov.uk/international/switzerland.htm
Just to be clear a person commits tax fraud when he intentionally pays too little tax.

Well, in the case of Inheritance tax, strictly speaking, they could not pursue you as you would no longer be around. The UK taxman may have a long arm, but not that long! My guess is if the amounts were significant enough, they would pursue the executors or the beneficiaries. Quite how they would do that and whether the swiss authorities would assist in the tax collection I don't know as I'm not familiar with cross border enforcement procedures but cooperation between EU countries and CH has moved on a lot since Marc Rich was in the headlines. I don't think it matters whether or tax evasion is a criminal offence per se. What matters is what is agreed between the two states in the Double Tax convention between them.

But it would have to be considered tax fraud in Switzerland and I am not sure that paying too little tax is tax fraud in CH. I believe it is tax evasion and thus not part of the agreement,

I really don't know whether cross border tax crimes are covered in the agreement or not and if it isn't what the chances are of it being included through future amendments to the protocol or other treaties like Schengen (which includes a lot of agreements other than cross border movements of people) and things like Switzerland's participation in implementing the European Savings Directive. All of these types of treaties chip away slowly but steadily at things like banking secrecy and cross border cooperation. At the end of the day the UK system relies on it's citizens disclosing taxable assets to it's tax authorities so by definition it loses tax revenue from liabilities which have not been declared which is why the penalties are so stiff when they do catch up with you. I have no idea what proportion of overseas IHT evasion cases it decides to pursue but that risk must increase in proportion to the amount of tax at stake. What I do know is that the UK government is 100% committed to pursuing tax fraud and closing loopholes. In fact they have an entire department focussed on identifying offshore evasion. It's very focussed on gathering information on the assets which it's citizens put in offshore financial centres like CH, Luxembourg etc to avoid tax and putting pressure on governments to agree to cooperate. At the end of the day it's up to the individual to decide whether to they want to base their tax planning on evasion rather than avoidance. But with professional help, there are plenty of ways to reduce potential IHT liabilities entirely legally. And as I've said before - unlike Income Tax, in the case of IHT it won't be an issue for you. It will be an issue for your executors and heirs.

What interests me is the original question about Swiss law on wills etc... which also raises the point of how to make a will which is valid in Switzerland and country of origin (in my case UK) when you have assets in both countries?
Does anyone know the Swiss law on execution of wills?
Is there a way of ensuring the same will is valid without having to make 2 different wills under different procedures?
Many thanks for information

I too have a query along similar lines as previous poster re: wills. My husband and I are both English but also have Swiss nationality too. We both made our wills in the UK prior to moving over here. Are they valid here also ? I must say I struggled a bit reading some of the other posts. Although they were written in laymens terms my peabrain still found them rather hard

Your UK wills are valid. But they must be consistent with Swiss law. Swiss Law defines minimum inheritance share (known as PflichtAnteil). That is defined as half the amount, which would be due without a will.

Example: without a will, the spouse gets 50% of the assets. Hence, the will cannot give less than 25% to the spouse.

Another example for 2 children: Without a will, each child gets 25%. With a will, no child can be lowered below 12.5%.