Married With a Buy-to-Let?
Form 17 Might Save You a Needless Tax Bill..
How to stop HMRC defaulting your rental income to 50/50 (when that’s not your reality)
This comes up a lot…
A married couple buy a rental property. One person puts in most of the deposit, or they agree the ownership should be uneven for sensible family planning reasons.
But when it comes to tax, HMRC’s default position is simple:
If you’re married or in a civil partnership and you own property jointly, HMRC assumes the income is split 50/50.
Even if you know that’s not how you’ve arranged things between you.
That’s where Form 17 can be useful, but only when it’s done in the right order.
The key thing to understand: Form 17 doesn’t create the split
Form 17 is not the bit where you “choose” how to split income.
It’s the bit where you tell HMRC what the beneficial ownership already is.
So if you want a 70/30 split (or 90/10, etc.), you usually need to do this first:
1) Put the beneficial ownership split in writing properly
This is where a Declaration of Trust (also called a Deed of Trust) comes in.
That legal document sets out the beneficial ownership in the percentages you’ve agreed.
So if the trust says the beneficial ownership is 70/30, that’s the reality HMRC expects you to be working from.
2) Complete Form 17 to match the Declaration of Trust
Once the beneficial split is properly documented, you complete Form 17 so it mirrors those same percentages.
This matters because HMRC expects the income split to follow the beneficial ownership split. It needs to line up.
3) Send the Form 17 to HMRC (on time)
This bit is where people slip up.
There’s a strict 60-day deadline from the date you sign the declaration, and it’s not retrospective, so timing is important.
Why people bother
Most of the time it’s because:
one partner is a higher rate taxpayer
the other partner has unused basic rate band or personal allowance
and the couple want the tax on the rental income to reflect their real ownership position
Done properly, it can make the overall household tax position much more efficient.
A few “please don’t accidentally ruin it” reminders
Form 17 only works for married couples and civil partners
you need a genuine beneficial ownership split (not just “we want it this way for tax”)
the paperwork has to match reality, and the form has to match the paperwork
it’s not backdated, and missing the deadline can make the declaration ineffective
Want us to sort it properly?
If you’re thinking this might apply to you, we can take it off your plate:
confirm whether Form 17 is appropriate for your situation
arrange the Declaration of Trust in the right ownership percentages
complete Form 17 so it mirrors the trust exactly
get it submitted correctly and within the time limit
and make sure your tax returns follow the correct split going forward
If you want, send over the rough split you’re aiming for and whether the property is already jointly owned, and we’ll tell you the cleanest way to structure it.
