1. to take the captains test which requires the ability to perform the bankai. Presumably, most candidates become captains using this method. At least three existing captains, including the Commander-General (Krullex), have to witness the test.

2. To have personal recommendations from at least six captains and approval from at least three of the remaining seven.

3. To defeat a captain one-on-one within 5 levels of eachother with at least 2 witnesses from the captain's division. Jay Fang is the only known captain to have achieved his rank using this method.