If you are under 21 years old and cannot show an independent ability to make the required minimum periodic payment on the account, the credit card company cannot approve your application without a co-signer, guarantor, or joint applicant. If you are under 21 years old, the guarantee may come from anyone at least 21 years old with the financial ability to make the payments, and does not have to come from your parents.

The person also must either be secondarily liable for any debt on the account incurred by you before you have attained the age of 21, or jointly liable with you for any debt on the account.

If you open a joint account with someone, this person generally is allowed to make purchases on the account. You are both equally responsible for making payments on the account, regardless of who made the transaction.

Warning: If anyone asks you to help them get a loan or a credit card by being a guarantor, co-signer, or joint account holder, and you agree to do so, remember that you are agreeing to pay back the loan. If the loan isn’t repaid on time, it may appear on your credit report and hurt your credit score. Also, if you or the other person fails to make timely payments, debt collectors might pursue you or you could be sued to pay the debt.