Yes, you can file your taxes now and submit your common-law's return at a later time. As per the TurboTax Article: "If you are married or in a common-law partnership, theCanada Revenue Agency (CRA) requires you to report your relationship status and information about your partner on your tax return. As a couple, you don’t file your taxes together. However, you can harmonize the information on your tax return to help decrease your taxes or increase your refund".