CRA indicates that adding a closely related party to ETA s. 156 elections does not require revocation of previous elections

CRA indicated that when the parties to a nil consideration (ETA s. 156) election (say, Company A and B) wish to add another member of the closely related group (Company C) as an electing party, it is not necessary to revoke the existing election, and it is sufficient for “Company C [to] simply file a new election naming Company A and B as closely related members.” However, if one of the three companies wished to leave the group, the filing of two revocations would be required.

Neal Armstrong. Summary of May 2019 CPA Alberta CRA Roundtable, GST Session – Q.20 under ETA s. 156(4).