The single return must be filed in the name and federal employer identification number of the parent corporation if the parent is a member of the unitary business and has nexus with Maine. If there is no parent corporation, if the parent is not a unitary group member, or if the parent does not have nexus with Maine, the members of the unitary business must choose a Maine taxpayer member to file the return. Once this filing member has been selected, it must remain the same in subsequent years unless an ownership change occurs or the filing member no longer has nexus with Maine. The return must be signed by a responsible officer of the filing member as the agent of all unitary business members subject to Maine tax. The Maine combined report of the unitary business must be attached to the Maine corporate income tax return. Members of the unitary group are jointly and severally liable for the tax of the members of the unitary group included in the combined return.
The applicable portion of Maine sales attributable to non-nexus entities is determined by applying a fraction to the total Maine sales of the non-nexus entities. The fraction is equal to the separate Maine nexus member's Maine sales attributable directly to that member (i.e., Maine sales before the addition of a portion of non-nexus affiliate sales) divided by the total Maine sales attributable directly to all nexus entities. A copy of the combined report must be attached to each of the separate returns.
18-125 C.M.R. ch. 810, § .05