We always love when a new card comes to the market.

Opening five credit cards within 24 months will render you ineligible for any further Chase credit cards, until that five number has dropped to, at the most, four credit cards within the last 24 months. While not published by the bank, the Chase 5/24 rule is widely accepted as truth by the miles and points community after years of shared and collected experiences.

Business credit cards do not, anecdotally, count in your Chase 5/24 total.

UPDATE: THIS OFFER HAS EXPIRED. THE CHASE UNITED EXPLORER BUSINESS CARD NOW EARNS 100,000 BONUS UNITED MILES FOR SPENDING $10,000 WITHIN THREE MONTHS OF ACCOUNT OPENING.

At some point on March 18, 2018 the biggest ever sign up bonus on the United Explorer Business Card will end. I'm guessing you'll have until the end of the day on Monday, March 18 to apply, as on united.com (as of Sunday evening, March 17) there is a banner that reads "75k BONUS MILES, 2 DAYS LEFT-- OFFER ENDS 3/18.