Me. Rev. Stat. tit. 36, § 1759

Either as a condition for issuance or subsequent to the issuance of a registration certificate under section 1754‑B or 1756, the State Tax Assessor may require from a taxpayer a bond written by a surety company qualified to do business in this State, in an amount and upon conditions to be determined by the assessor. In lieu of a bond the assessor may accept a deposit of money or securities in an amount and of a kind acceptable to the assessor. The deposit must be delivered to the Treasurer of State, who shall safely keep it subject to the instructions of the assessor.