Past debts are a major problem for people applying for new credit. Here are a few things that can help especially if the default is unfair.

If you believe a default to be unfair, then your first course of action is to contact the company or lender and lay out your terms. If the case is disputed the company can wipe the default from your file. If that fails then your next step is to complain to the financial ombudsman who is the free and independent arbiter of dispute. They can rule that the debt can be wiped from you file if they believe it to be unfair.

If you are prepared to repay the debt in part or in full then contact the lender to which you owe the money. As part of the agreement you can request that a "Condition of settlement" be agreed to, which wipes the debt from your credit file once payment has been made. This can be arranged for disputed defaults.

If either of the two previous courses of action fail then you can add a notice of correction to your credit file. A notice of correction should state clearly why you think the default to be unfair. For example, "It was a joint account I held with my ex partner, who ran up the debt after we had parted". These will slow down the whole process of a credit application because a lender will be likely to look into these manually. But if the default is serious enough, then adding a correction notice is worthwhile if it helps.

Final Note

Defaults should only be disputed if you believe them to be justifiably unfair.