You can pay your Maryland taxes with a personal check, money order or credit card. All due dates assume that the date falls on a business day.If the due date falls on a holiday or weekend, the due date will be the next business day. Your first payment is due 30 days after the clerk approves your request and once a month for the nine months after that on the date noted on the agreement. SemiAnnual tax bills are due September 30th of each year. The second installment is due December 31st. If you are ordered to pay a fine due to a traffic violation, but are unable to pay it in full, you may be eligible for an installment program.