Tonnage tax option: application process, Joint Commissioner approval or refusal timelines revised, approval effective from relevant assessment year. A qualifying company may opt into the tonnage tax scheme by prescribed application to the Joint Commissioner, who may call for documents to verify eligibility and must approve or refuse the option in writing after affording a reasonable opportunity of being heard. Statutory time limits require the Commissioner to issue orders within the prescribed period from receipt of the application (with an extended timeframe for later-filed applications). Approval takes effect from the assessment year relevant to the previous year in which the option is exercised.