When applying for a mortgage you should consider the redemption penalties you will face as you might be in able to pay off the mortgage early or switch your mortgage to another mortgage lender for a better rate/agreement down the line.

Generally these penalty charges are unavoidable in the sub-prime mortgage market, however you need to ensure they don't last for more than 3 years (mortgage terms are generally for two, three or five years). If they did, they would prevent you remortgaging once you have improved your credit status.

If the purpose of taking a sub-prime deal is to help restore your credit score and allow you to move to a better deal at a later date, then it is worth considering an interest-only mortgage. Your payments will be smaller, making them easier to meet in the short term. But it is advised that you consider switching to a repayment mortgage asap.. Whichever option you chose, it's essential that you make sure you do not miss any mortgage payments or you risk damaging your credit history further.