Licenses expire on the last day of June following their issuance or renewal and are invalid on that date unless renewed. The secretary of the board shall notify, at his last registered address, every person registered under this chapter of the date of the expiration of his license and the amount of the fee required for its renewal for one year. The notice must be mailed at least one month in advance of the date of the expiration. The board shall set the annual renewal fee by regulation. Renewal of licenses for the following year may be effected during June of the year in which the license has been issued or renewed by the payment of the renewal fee. The licenses also may be renewed during the ensuing three months by the payment of an additional fee for each month or portion of it that payment is delayed beyond June. The fee must be set by the board by regulation. The board shall make an exception to the renewal provisions for a person who is in the Armed Services of the United States. The board shall develop regulations for continuing education or other assessment of continued competence.