Hi Jelly,
When you are filling in your student finance application you will be asked under the Living Costs section whether you wish to apply for a Maintenance Grant based on household income.
If you're under 25 years old you'll be asked to provide the details of your parent(s) depending on your circumstances. Your parent(s) will then be asked to provide financial information about your household income to determine whether you are eligible to receive a Maintenance Grant and, if so, how much.