CRA indicates that a common-law partners’ separation agreement can engage the s. 73 or inter-RRSP rollover even if technically they have no legal rights to settle

Ss. 73(1.01)(b), 146(16) and 146.3(14) provide for a rollout to a common-law partner or a partner plan pursuant to a written separation agreement governing the division of the common-law partners’ assets in settlement of their rights arising on the breakdown of their relationship. CRA considers that, although there is no right in Quebec arising out of a common-law partnership (as per Éric v. Lola, 2013 SCC 5), it nonetheless “is not impossible for the annuitant to determine to create rights under a written separation agreement relating to the division of property with the annuitant’s common-law partner or former common-law partner” – and that “such an agreement could be concluded at the time of separation, whether or not a common-law union agreement providing for the rights of each in the event of the union's failure has been previously signed.”

Neal Armstrong. Summary of 6 October 2017 APFF Financial Strategies and Instruments Roundtable, Q.1 under s. 146(16)(b).