Some lenders ask borrowers with bad credit or no credit to get a cosigner before they're willing to approve their loan. If you need a cosigner to boost your credit for a car loan, there are two main requirements they must meet: A good credit score: If you're struggling with your credit, the lender will require your cosigner to have good credit. Typically, this means they want the cosigner's credit score to be around 700 or higher. A qualifying income: A cosigner will also need to meet the lender's minimum income and debt to income ratio requirements. For most subprime lenders, they require borrowers to make $1,500 to $2,000 a month before taxes. The debt to income ratio is found by dividing the total amount of a borrower's monthly bills by their pre-tax monthly income, and most bad credit lenders don't want this to be higher than 50 percent. These requirements give the lender the confidence needed to approve your loan. A cosigner signs the loan contract alongside you � the primary borrower � which means they're legally bound to it. These measures confirm that the cosigner can meet the obligations of the loan in the event you don't. Keep in mind that both the cosigner and primary borrower have to meet the income and debt to income ratio requirements individually. The incomes of the two can only be combined to meet the income requirements when the primary borrower and cosigner are spouses.