I am sponsoring my partner as a common-law partner for Canadian immigration. We plan to mail out our application next week. However, we recently got engaged, but do not intend on getting married until later next year. How does this affect our application? Should we include details of our engagement (ie. photos), or leave this event out of the application? Thanks!

Put it in!

Ahem. Include the evidence of engagement as it is supporting evidence of the common-law relationship. More so than, say, holiday pictures or shared gas bills which you will have included.