First get approved for vendor accounts that report to business credit reporting agencies. Once you develop that initial business credit, buy what you need and pay it back, which helps build your credit score. Credit is reported to Experian, Equifax, or Dunn & Bradstreet.
Seek to establish ten (10) and more vendor accounts, but if you have 3-6 accounts reporting, you can start applying for the next tier. Once you have used your business credit and showed responsibility in paying, then request for an increase in limits. Higher credit limits also assure banks and other credit issuers of the business history in paying obligations. They are essential to getting funded as your business seeks higher levels of approvals. This will help you in getting approved for small busines credit cards.