As joint tenants you will be taxed on 50% of the income each. It may be more tax efficient to split your shares unequally, as tenants in common, as you'll be taxed according to your beneficial shares.
As a married couple or civil partners, you'll still be taxed 50/50. You can adjust your tax for uneven shares, using HMRC form 17.
Parachute Law Ltd does not provide stamp duty, bankruptcy, financial, tax (including capital gains tax, inheritance tax or rental income tax) advice and does not advise you as to the suitability of any tenancy arrangement for your particular circumstances. We can introduce you to a professional accountant if you would like tax and financial advice specific to your situation and assets.