I’m afraid to say it is the position by default. If you live with your spouse or civil partner, the income from property held in joint names will be split in equal shares; regardless of any other circumstances.
However, clearly this puts married couples at a disadvantage to unmarried couples and therefore, there is now a way that married couples can apply to have the income allocated in an unequal way.
It does involve an application process though and you’re unlikely to be successful if for instance, your motives are only to shift more income to an individual paying tax at a lower rate. I would therefore encourage you to seek advice from a professional such as your local TaxAssist Accountant.