The fastest way to build credit, especially for those who have a limited credit history, is to piggyback on the credit of someone else. Examples of credit piggybacking include getting a cosigner or guarantor in order to qualify for credit, opening a joint account with someone, or being added as an authorized user. Once you have started to establish a credit history by piggybacking, you can continue to build up your credit by opening up more tradelines. You can also add tradelines to your credit file that already have years of perfect payment history to help balance out the effects of any derogatory accounts. Remember, tradelines are the foundation of building credit because all credit starts with tradelines.