Shared Ownership - To Staircase? SDLT tax implications?

BushyGround89

Hi Everyone

Myself and wife bought a 45% share in a resale property in London in February 2017. The total value of the flat was £490,000 so our value was £220,500. We paid £1,910 in SDLT. The seller’s solicitor confirmed that the buyer only paid stamp duty on the value of the portion of the property they purchased so we are eligible for SDLT on any future staircasing.
We are now looking to staircase. We can't afford to go to 100% but could potentially go upto 75/80%. I have a few questions regarding this on SDLT and possible implications when it comes to selling at a later date:

1. I understand if we go upto 80% then no SDLT will be due. If we then decide to go upto the full amount of 100% will we have to pay SDLT on everything from 45% to 100% or would it be from 80% - 100% ?
2. Selling the property at 80% - I understand this might be more difficult to do then the current 45%. Do people have any experience of selling at 75/80% ? Further to this if we do struggle and have to sell on the open market at 100% are we liable for the one off purchase on the day to 100% in regard to SDLT or is there a way around this? I've seen some mention of Sub Sale relief - Seems to be conflicting information around if we will be eligible for this?
3. Would there be value in considering putting some money into pay off more of the mortgage? We do intend to stay at the flat for the next five or so years but do worry about a recession (I know this is a $$$ question but any thoughts would be appreciated!)

Thanks for any help or tips you might be able to share - I'm at a serious wits end wondering what to do!

Thanks
Luke

BushyGround89

Ooop forgot my final question...

4. With the changes to SDLT and the threshold for £500k properties. Do people think that this will have an affect on people purchasing flats around this figure.. I.E is it very unliukley we will be able to make much growth in our property as if it is marketed for say £520k most FTB will look to bring this under to give them the exemption.

Again any help much appreciated.
Luke

SDLT_Geek

Here are answers to the SDLT aspects of your questions:

1. SDLT would be due taking account of all the payments you made to go from 45% to 100%, but only actually levied on the amounts taking you over 80%.

Say for example that you pay £178,500 to go from 45% to 80% and then £104,000 to go from 80% to 100%. You have paid a total of £282,500 on staircasing.

SDLT due on the whole £282,500 would be £4,125. But you would pay SDLT on a fraction of this.

The fraction is £104,000 / £282,500. That gives an SDLT of £1,519 on the payments taking you over 80%.

2. If having got to 80% you try to sell, but cannot sell at 80% staircased, you might need to staircase to 100% "back to back" with the onwards sale. You would not be entitled to subsale relief (you do not pass on the same "subject matter of the transaction" that you acquire).