See also: Six alternatives to wedding loans
Capital Gains Tax risk
A married couple can only have one principle private residence between them for capital gains tax purposes. Capital Gains Tax has to be paid on any home that is not the owner's main home - but married couples can only have one. So, when the other home is sold, tax will be due.
Stamp Duty surcharge
Similar to Capital Gains Tax, married couples can only have one residence for Stamp Duty. The surcharge of 3% will be payable if one spouse owns a property and the other buys a second one - even if only one person's name is one the deeds.
Taking on a mortgage
Normally items passed between spouses are tax-free, but there is one major exception to this, if a property is mortgaged and passed from one partner to the other the receiving partner must pay Stamp Duty on the mortgage debt.
This can be claimed by couples where one is a non-tax payer and the other is a basic rates tax payer. Married couples allowance is a different benefit that can be claimed by older couples and can be worth up to £835.50 per year, if you were born before 1935.
Inheritance Tax Benefits
While married couples can pass assets between them Inheritance Tax Free, it's not the same for non-married couples. Anything above the normal nil-rate band of £325,000 would be subject to tax at 40%. A married partner could also pass on their allowance to the other, meaning the surviving spouse could pass on £650,000 tax-free.