Me. Rev. Stat. tit. 36, § 1756

Every seller of tangible personal property or taxable services that is not required by section 1754‑B to register may register upon those terms that the assessor prescribes. Upon registration, the seller has the rights and duties of a person required to be registered and is subject to the same penalties, except that the seller's liability may be limited to tax actually collected. The seller so registered may at any time surrender the seller's registration certificate and request that the registration certificate be canceled. Upon receipt of the certificate and request, the assessor shall grant the cancellation, if it appears to the assessor that the seller has satisfied all liability to the State and that the seller is not required by law to register. Upon surrender of the certificate, the seller must cease to collect sales or use taxes upon sales that occur on and after the date of the surrender.