August 28, 2026 update: Rakuten has added the Chase Ink Business Cash to this promotion, offering the same $100 cash back or 10,000 Bilt points available with the Ink Business Unlimited. The Ink Business Cash also currently offers an elevated 100,000-point welcome bonus and has no annual fee. The same advice applies regarding two-player mode and a referral bonus for new Chase for Business customers being the better play if it's available to you.
Rakuten is offering a $100 bonus (or 10,000 Bilt points if you've selected Bilt as your earning preference) when applying for the Chase Ink Business Unlimited as a new Chase for Business customer. That stacks with the card's current elevated welcome offer of 100,000 Ultimate Rewards points, creating an outstanding return on a no-annual-fee card. If you're in two-player mode, however, the 40,000-point referral bonus is generally the better play. The catch is that the applicant must be a brand new Chase for Business customer to be eligible for that referral offer. If your Rakuten account is set to earn Amex Membership Rewards, you will not see this offer. Your Rakuten earnings must be set to cash back or Bilt points.