Inherited property

[Thingsthatgo]

Please can you tell me the tax implications of this scenario... (ie would capital gains be due?)
MIL has inherited a property from her mother. It's going through probate but there will be no inheritance tax due. (MIL's father died 12 years ago, property and cash worth approx £700k all going to MIL)
MIL would like to move into property and sell her own house. She has lived there for 40 years, it's worth around£550k (£400k more than when she brought it.)
She'd like to spend some time and money on her inherited house before she moves in.
Is CGT due on the increase in value of her house? Does the amount of time she waits to move and sell old house have implications?
I know she needs proper legal advice, but I am just doing some research in order to prompt her to get advice IYSWIM! She is a bury your head in the sand kind of person.

Surely a probate solicitor is already extensively involved? Just drop them a line to ask

My understanding is if your MIL has lived in her home for 40 years and is only moving out when she sells, there is no CGT to pay. If she moves out before she sells there may be CGT on any increase between the date she moves out and the date she sells.

I assume her mother died recently, so potentially her estate may have a CGT liability from the date of her mothers death to the date it becomes MILs primary home.

As a pp said you need proper legal advice.

Thanks, MIL's mum died in August, and she has only just beginning to think clearly again. It has only just occurred to her that moving in her mum's house might be a good idea. I want her to consult her solicitor about it, but she cannot see any reason to. I wanted to explain to her why she needs to ask the questions, and so it would help me to have a vague idea.

Her own house was £150,000 when she bought it 40 years ago and it has only increased by £400,000 in that time? Those figures look slightly off.

I don't think ther is any CGT when selling your main residence.

CGT isn't payable on your main residence.
There is some overlap time allowed anyway I think.

At most the only CGT would be on the inherited house between probate value and moving in value, which is likely to be negligible.

Just done a quick search and it looks as if there can be a 3 year overlap.

Is there any other beneficiary to her mother’s estate?

@TeenDivided 3 years would be plenty! Thank you, I shall ask her to talk to her solicitor.
The figures may be off on the house price in 1983... it was a number she gave me but I suspect that she was guessing/remembering wrong.
Thank you all for your help.

@Paltrypam no other beneficiaries.