Subject to § 12–308.1 of this subtitle, unless a license is renewed for a 2–year term as provided in this section, the license expires on the first May 1 that comes: after the effective date of the license; and in an odd–numbered year. At least 1 month before a license expires, the Board shall mail or electronically transmit to the licensee: a renewal application form; and a notice that states: the date on which the current license expires; and the amount of the renewal fee. If an electronic transmission under paragraph (1) of this subsection is returned to the Board as undeliverable, the Board shall mail to the licensee, at the last known address of the licensee, the materials required under paragraph (1) of this subsection within 10 business days of the date the Board received the notice that the electronic transmission was undeliverable. Before a license expires, the licensee may renew it for an additional 2–year term, if the licensee: otherwise is entitled to be licensed; pays to the Board a renewal fee set by the Board; and submits to the Board: if contracting in the name of the licensee or another person to provide plumbing services, proof of the liability insurance required under § 12–501 of this title; and a renewal application on the form that the Board provides. The Board shall renew the license of and issue a renewal certificate to each licensee who meets the requirements of this section. The Secretary may determine that licenses and certificates issued under this subtitle shall expire on a staggered basis.