Security deposits may only be required from new non-residential accounts; or from non-residential accounts for service of a similar character, at any location, under any name, if this service has been properly terminated during the last 18 months due to non-payment; or if a non-residential account has failed to pay at least two bills, not reasonably in dispute, within 45 days from the date of receipt of each such bill during the same 18-month period.
220 CMR, § 26.02