There are normally two bills per year. The first bill of the year is an estimate, usually based on one half of the previous year’s tax. This tax bill, printed and mailed out near the end of May, is due July 1st. The tax rate is set by the State of New Hampshire Department of Revenue in the fall of the year after which the final bill is printed. The final bill is calculated using the new rate multiplied by your property’s assessed value as of April 1st less any payments made on the first bill. Mailed in the middle to end of October, the final bill is usually due December 1st each year.