CAT liability on UK inheritance

I'm confused and can't ring tax adviser until Monday. Can someone shed some light on the following?:

Inheriting cash from Uk bank account. Probate has been applied for in Uk. Amount of cash is £15k. My understanding is that there will be no liability in Uk as UK threshold is circa €300k.

My understanding is that my Irish liability will be 20% of €20k (value of sterling calculated in Euro based on valuation date) as threshold of €500k exceeded in Ireland.

Should euro equivalent of sterling figure be included in calculation of CAT liability when paying Revenue tax bill?

You say you are inheriting €20k from UK, who are you inheriting from, i.e. what relationship is the deceased to you?

When you say your €500,000 threshold has been used up, can you explain this a bit more?

The rule is, as far as I know, that when you are resident or ordinarily resident in Ireland, all property worldwide is liable to CAT (Gift and Inheritance Tax)

So the only way, in my view that you could be liable to Irish tax on the UK bank account is if you have already used up the threshold applicable to the person you are taking the bank account from in UK.