English testator with a property in Canada

A client of mine has recently purchased a small property in Canada, British Columbia to be precise. She says that the lawyer in Canada has advised her to update her English will to reflect this because if she does a separate will in Canada she will pay two lots of tax,one here and one there. Both she and her husband are British nationals and domiciled here. Currently their estates are hovering around the IHT threshold but that could change between now and their eventual deaths.

I realise we could re-seal a British grant of probate in Canada but I am not sure about the tax point. Does having a separate will affect the tax position ?

Mrs J E Bennell