Do we need to pay Inheritance Tax

Keep_pedalling

IPDI trusts are a great idea if the beneficiary is a surviving spouse or civil partner, but it becomes a bit tricky if the beneficiary is a friend, unmarried partner or a child  as there is no spousal exemption or transferable NRB available. If you happened to die while being the sole beneficiary of a £550k trust then that trust forms part of your estate for IHT purposes, and if you are single and have no children that takes you deep into IHT territory.

If the plan in the short term is to sell and buy something smaller with your share of the proceeds then perhaps you should consider a deed of variation to do away with the trust. 

As for registering the trust I know it is 2 years where a spouse or civil partner are concerned not sure if you need to do it faster if it is anyone else.