Minimizing US capital gains tax on sale of primary residence in the UK

Hi everyone!

Has anyone found a suitable tax solution to minimizing US Capital Gains Tax on the sale of a primary residence (i.e. family house) in the UK?

I understand that a US taxpayer can claim an allowance from US Capital Gains Taxes on the sale of their primary residence abroad:

* Filing Single:  Up to £250K USD
* Filing Married:  Up to £500K USD (not sure if this applies to Married - Filing Separately, Head of Household or both)

With house prices in London continuing to go up, the current allowances don't cut it for the sale of a modest terraced house in London...

Would getting a legal Joint Ownership Agreement (50/50 ownership) with my spouse (non-US citizen or resident) help shield half of the house sales value from the IRS, leaving the other half for the US taxpayer to apply the allowance to minimize the capital gains tax liability? 

I take it the IRS would want proof of my spouse's contributions to the ownership of the house from my perspective as the US taxpayer, since they have no legal jurisdiction over my spouse (or her finances - since she is not a US citizen or resident) to provide any proof (multiple tax treaties and international law).  What kinds of proof would the IRS be asking for in such a situation?

Are there any better tax solutions to this problem?

Turning in my US passport like the London Mayor Boris Johnson is not a solution or an option.  Sorry.

I would like to hear from others on this subject.

Thanks in advance.

If you are joint tenants or tenants in common then I'd only declare the portion of the house that you own for CGT purposes if you file MFS in the US.

I think it's only the tenants in common option that allows you to declare only the part of the property that you own.

It you are joint tenants then you each own the whole house jointly, with right of survivorship and the IRS would want you to declare the full value.

If you are tenants in common then you each own the house in whatever proportion you agree.  50/50 is normal but it can be any proportion you choose. 

You'd need to ask your solicitor to draw up the appropriate deed when you buy a house. 

There are several possible solutions to this. Have you asked your tax adviser and/or accountant? What advice did you receive when you bought the property and obtained a mortgage? What advice have you received since from your existing tax adviser?

Thanks WeWallace and Nun.  This is the direction and information I was hoping to hear as a potential solution.

Again, thanks!