Two principle dwellings for stamp duty

[Pinsneedlesok]

DP and I got together 15 years ago. We both had children from previous relationships living at our respective homes. It worked for us to stay living in our own places. We spend 3/4 nights a week at one or others homes but maintain totally separate homes.
Now our kids have all moved out (or almost) and DP has just retired, we are thinking of getting married and living in only one house. In practice we would probably sell both homes and buy a house together.
The question is stamp duty.
As I understand it, at the moment we both have a principal residence free of SD as we don't live together and aren't married.
Should we not get married till one property is sold? Or would we only pay SD on the rise in value between the marriage date and when we sold (which might be a year or so).
My house is worth about £700. Bought for £300 23 years ago.
His is worth about £400, bought for around £200 at a similar time.

Not what you asked and you may know this already - additional stamp duty that you’ve paid out for the new home, can be claimed back if the second home is sold within 3 years of buying the new main residence.

Are you thinking about Capital gains tax rather than stamp duty? Stamp duty is paid on purchase of a property and id a percentage of the purchased properties value. It isn't paid on the sale of a property and it isn't calculated on the ride in value.

Oh yes I am ?!?! Will edit post if I can work out how to!

I can't see how to edit the original post, but yes I meant capital gains tax not SD!
So how does getting married and moving in together affect the situation. What do we need to do to make sure we don't lose that benefit?
Thanks :)

You get PPR (principal private residence relief) for all the time you have lived in the house you are selling plus 9 months after you have moved out. Getting married doesn't really have anything to do with it if your house is in your name and his house is in his name only and you don't change that upon marriage.

That is wrong. Married couples can only have one PPR, regardless of where they are living. But the last 9 months is exempt, as is the period before marriage when it will qualify for PPR. So you will only have to pay CGT on one of the houses and on the period between marriage and sale less 9 months.

Personally I’d sort the housing and then get married, if only because planning two sales, a purchase and a wedding at the same time feels horribly stressful, whereas a nice relaxed wedding after moving into your new forever home feels lovely. But also be aware that any deed of trust or tenants in common arrangements to protect your share need to be explicitly drafted to be in anticipation or marriage, otherwise they will be void when you marry.

Stamp duty is also relevant. If you buy the new house before either of the others sell you will need to pay a higher rate. You can claim that back if you sell the other house within three years, but it is a cash flow issue.

Whilst figuring all this out, don’t forget to make new wills as soon as you marry, own the house as tenants in common in the same proportions as how the house was funded.

Yes sorry I assumed buying a house together and that becoming the new PPR was going to happen before marriage. Therefore the PPR relief available for the time living in the houses separately and the last 9 months would be unaffected.

Stamp duty is paid on the value of the house you buy together and is at a higher rate if either of you will still own another property at the moment of that purchase. It doesn't matter when you get married. Put both houses on the market. When the first one sells, stamp duty is irrelevant because it is charged according to the eligibility of the buyer not the seller. When the second one sells is when you can buy your together home. What you mustn't do is buy your together home before the sale of the 2nd original home.