Your disposable income rating is calculated based on details you’ve given us like your income, number of dependants and rent or mortgage (which you can edit in your account settings), as well as data from your credit report. This includes your loan and credit card balances - even if you’re paying them off in full by the end of the month - and any other debts you have.
Lenders then estimate your overall expenditure using data from sources like the Office for National Statistics for someone ‘like you’. As our scores try to mimic this process, your disposable income rating may not be entirely true to life. Spending less won’t help boost it either, though paying off existing debts (or using less credit) might.
Remember, disposable income is just one piece of the puzzle - your credit report and overall affordability matter too.