How much deposit you’ll need to put down will depend on your individual situation, and will vary between lenders. Lenders have their own criteria to work out how much of a risk it would be to lend money to you with a CCJ.
Generally, the more money you can put down up front, the less of a risk you pose. This is especially the case if you have a CCJ. The bigger your deposit, the less money you’ll need to borrow (LTV), and the better your interest rate will be. Having a bigger deposit shows the lender that you’ve been savvy with your savings, and have got a good grip on your finances.
However, if you can’t save a lot of money for a deposit, there are schemes available such as Help to Buy and Shared Ownership which only require a smaller amount up front. You can read more in our guide: Help Schemes for First Time Buyers.