N.H. Rev. Stat. § 35-A:32
The bank is hereby authorized and empowered to enter into such agreements or contracts with any banks, trust companies, banking or financial institutions, within or without the state, as may be necessary, desirable or convenient in the opinion of the bank for rendering services to the bank in connection with the care, custody or safekeeping of municipal bonds or other investments held or owned by the bank and services in connection with the payment or collection of amounts due and payable as to principal or interest, and for services in connection with the delivery to the bank of municipal bonds or other investments purchased by it or sold by it, and to pay the cost of such services. The bank is further authorized and empowered in connection with any of such services to be rendered by any such banks, trust companies or banking or financial institutions as to the custody and safekeeping of any of its municipal bonds or investments, to require security in the way of collateral bonds, surety agreements or security agreements in such form and in such amount as, in the opinion of the bank, is necessary or desirable for the purpose of the bank.
RSA 35-A:32
1977, 491:1, eff. July 1, 1977.