Inheritence Tax: Blood uncle wills to aunt who wills to me

I had an uncle who was a blood relation. He died a few years ago and His estate went to his wife. His wife has since died and willed everything to me. On first inspection you'd expect to pay normal inheritance tax without any allowances because the aunt was not a blood relation.
However I know in the UK that they take into account that the uncle was originally a blood relation and since his estate went to his wife and now that estate is being passed to me, part of this estate is in effect from my uncle who is a blood relation. I should be allowed some allowances on this inheritance since my uncle was originally a blood relation. Does anyone know if the same applies here?

When it comes to inheiritance tax, you will fall into Category C which has a tax free exemption of of 16,700 euros. That is the first 16,700 is tax free. Every thing above that you pay CAT tax at a rate of 20%.

If you were inheiriting directly from your uncle, you would fall into Category B which has a tax free exemption of 33,500 euros. You are not. You are inheriting from his wife. To the best of my knowledge, Revenue does not give a you an additional exemption based on you having a blood relationship with the person who was the original source of the inheiritance.

How long between the two deaths? Would you say that your uncle left everything to his wife on the understanding that she would in turn leave it to you? If so, perhaps you could make a case to the Revenue. What type of assets are involved- land? a business?