What is a form 17 and how can it save tax?

Usually where a married couple (or civil partners) own a property jointly any investment income from that property is split equally. If one spouse is a basic rate taxpayer, and the other is a higher rate taxpayer this may not be advantageous. A form 17 can allow you to split the ownership for tax purposes. The declaration on form 17 sets out the beneficial ownership percentages and would ensure that each spouse was taxed on that basis. You could therefore allow 99% of the income to be taxed on your spouse with only 1% on you (eg if you were a higher rate taper and your spouse wasn't). Note though that this would only apply where the beneficial interests in the property actually were 99/1 (eg your spouse received 99% of the rental income etc). Once a declaration on form 17 is made it remains in force until the interests in the capital or income change. There's more on this in this article:Jointly held property and income tax