N.H. Rev. Stat. § 21-J:14-j

I. The intergovernmental agreement used to form a cooperative assessing district shall substantially conform to the provisions outlined in RSA 53-A:3 and shall include the following: (a) A district cost allocation formula based in whole or in part on the number of parcels of real property in each member municipality. (b) A governing board on which each municipality in the district is represented by at least one member who has at least one vote. (c) A term of initial membership of at least 5 years. (d) A requirement of at least 12 months written notice and a vote of the municipality's legislative body before a member may withdraw from the district. (e) Provisions for holding a withdrawing municipality responsible for payment of its proportionate share of future district expenses to which the district may be committed because of the withdrawing municipality's membership such as capital costs and retirement costs. (f) Provisions that require a municipality which joins a district to provide its annual pro rata share of the district's budget without regard to whether or not said share is approved and supported by the governing body, the budget committee, or the legislative body of the municipality. (g) Provisions for administratively attaching the district staff to a political subdivision for the purposes of accounting, payroll, retirement, insurance, and fringe benefits, and for compensating that political subdivision for these administrative services. (h) Provisions for compensation and oversight if private entities are hired by the district, rather than staff administratively attached to and serving as employees of a political subdivision. (i) A formula for staffing the district with full-time, trained, and certified professional appraisers which may be based on the number of parcels and types of properties found in the district and other necessary staff. II. All appraisers employed by a district shall meet current standards pursuant to RSA 21-J:14-f.