You can apply for a regular travel rewards credit card to fly United Airlines. For example, with the Discover it® Miles card you will be able to earn unlimited 1.5 miles on all purchases. This card does not offer a sign-up offer we are used to seeing on travel credit cards, it allows you to make your sign-up bonus as big as you wish. All the miles you’ve earned by the end of your first year will be matched if you are a new cardmember. Thus, if you earn 30,000 miles, you get 60,000 miles. You can redeem miles for any flight, including United Airlines, and other travel expenses. This card comes with no annual fee, no foreign transaction fee and 0% intro APR on purchases for 14 months (after that the ongoing APR will apply).