I'm worried I've made a stupid mistake that will mean my siblings and I have to pay more IHT.
Background: Dad died last year leaving his entire estate and house to mother (she is on the deed as well) . Her Will is a mirror of his and her estate will be split between me and my siblings when the time comes since dad is dead. Probate is still not completed for dad as his estate is fairly large (estimated at about 1million). My mother is showing early signs of dementia (still has capacity most of the time) and my sister and I have LPA. Mother lives with sister but will likely need to go into a home soon. Mother has in excess of £400k in her own accounts and will get a substantial widows pension soon.
We have had three different solicitors from the same firm work on dad's probate due to staff changes. The previous solicitor (a locum) suggested we do a Deed of Variation so that dad's estate could pass directly to us children since mum didn't need the money (and it was proving hard for her to gift us any money as banks view her as a vulnerable customer and kept freezing her accounts if transfers made). So we all agreed on the DOV (but I was the main sibling to discuss it with the solicitor). It's signed and done so can't be revoked but I'm sat here feeling worried. Am I right in thinking that we are now going to have to pay IHT where none would have been due if we had just left things alone and not bothered with the DOV? Feel like I've cost my siblings a lot of money.
I understand that no tax would have been due for mum to pay as dad was leaving everything to his wife. But now that my siblings and I are the beneficiaries (thanks to the DOV), we will need to pay 40% of anything over £500k (£325k threshold plus property allowance)? Is that right. But if we had left well alone and got nothing until mum passed away, mum would use dad's £500k allowance in addition to her own £500k allowance so no tax would be due unless her estate exceeded 1 million? Is that correct?
Thanks in advance. And yes, I know I'm lucky and am very grateful for this money.