Agreed with above, simply having testimonial letters does NOT prove common-law. Testimony letters are secondary pieces of evidence. IRCC wants to see hard evidence of cohabitation like a joint rental/lease agreement, mail to both of you going to same address, joint financial accounts, joint insurance, etc etc. Some official documents should be able to prove the cohabitation started on the day you said it did.
If all you have to prove you started cohabiting are letters from friends/family, you could have a hard time.
At the very least if you lived with his father from the very beginning then you should create an official rental agreement and have it back-dated to when the cohabitation started, signed and notarized. You can download lots of sample rental agreements from the internet to use as a template (just Google it).
Also the 30 day separation may be more serious that you think. We have seen other cases rejected for a similar break, since the visa officer thought it broke the cohabitation so would have had to reset the clock to zero at that time. However we've also seen successful cases with similar length breaks. In the end the only decision that matters is up to the visa officer processing your file, and if they personally view the temporary separation as too long to continue common-law qualifying.
If all you have to prove you started cohabiting are letters from friends/family, you could have a hard time.
At the very least if you lived with his father from the very beginning then you should create an official rental agreement and have it back-dated to when the cohabitation started, signed and notarized. You can download lots of sample rental agreements from the internet to use as a template (just Google it).
Also the 30 day separation may be more serious that you think. We have seen other cases rejected for a similar break, since the visa officer thought it broke the cohabitation so would have had to reset the clock to zero at that time. However we've also seen successful cases with similar length breaks. In the end the only decision that matters is up to the visa officer processing your file, and if they personally view the temporary separation as too long to continue common-law qualifying.