We applied in October 2018 as inland common law and just got the DM letter last week. Here are some of the things that we provided as proof (I know some won't apply in your case but I may as well put them out there as others may read this).....admittedly, some of them are pretty flimsy on their own, but I think all together, it gives a pretty good cohabitation picture :
- Addendum to lease agreement, showing that I added him since he wasn't originally on the lease
- Rental increase notice with both our names
- Tenants' insurance with his name on it
- One Hydro bill with both our names on it
- One phone bill with both our names on it
- My paystubs and bank statements (I'm the only name on it) showing my address for 12 months
- An invoice from the gym,, showing that we had a "family membership" under both our names and with our address
- A printout of my partner's public library account, showing his address (to get a library card here, you need to provide proof of address)
- A postmarked envelope from the travel insurance company with my partner's name and address on it
- Some of my partner's bank statements, showing just his name (not mine) and address on it
- The paperwork from when my partner added me to his bank account - dated, had both our names/address on it
- Amazon receipts with date, address, and partner's name - these were our saving grace. He managed to buy several different things all in different months, and they all had his name and address on them, along with a date.
- A pharmacy receipt from when my partner got his flu shot - it was printed more like a prescription printout and had name, address and date on it.
- Printout from my CRA account showing I'd updated my marital status to common law (I believe this had the date we became common law on it as well)
- Various receipts and invoices covering the 1 year cohabitation period generated when my partner went to a walk-in clinic and made claims on his travel insurance.
- A car rental invoice - at that time, I didn't have a driver's license and he did, so it was rented under his name. The invoice listed the date, his name, and full address.
- After sending off the application, we later found all the paperwork from when he opened his Canadian bank account at TD - it had name, date and address on it. We didn't send this in the application but held on to it and kept it in mind in case they asked for further proof (they didn't).
- Visa statement showing his name and address - I added him as an authorized user to my credit card, so this did double duty as "proof of cohabitation" and "proof of financial mixing/proof of relationship")
When we were compiling the paperwork, I made up a chart (for our reference only; I didn't include it in the final app) that was divided by month and had a column for him and a column for me. I basically made sure that I had at least one thing for each of us from each month. If we didn't have decent proof, we were going to hold off until we did. We were missing something for him from February, but we ended up having a friend write us a letter of support and she mentioned that we both house-sat for her in February 2018. That was the only month that was missing, and it was just for him, so we decided to go ahead and cross our fingers.
On top of all that, we had other stuff listing each other as common law partner (benefits at work, insurance policies, visa card etc). That proved the relationship side of things, but not the cohabitation as we had a lot of stuff listing each other that wasn't dated.
I've heard they can be very picky, so unless you're satisfied that you have enough proof to convince a total stranger that you've been living together for 12+ months, hold off sending it in. We cut it super close (moved in together on September 29; sent application around October 6 of the following year) and I would
not recommend doing that. The burden of proof is high and it's nerve-wracking, and having to wait a month or so more is way better than stressing about getting your app denied.
Also, we ended up getting pretty proactive/politely aggressive about getting some of these pieces of evidence. In many cases, the bank/car rental company/whatever wouldn't have given us a photocopy of the record we used as evidence, because it's just such a routine item. We had to explicitly say "We are applying for PR and need to prove cohabitation," and then they would make us a photocopy. We spent about 20 minutes trying to get the gym to print us a decent invoice showing name and address, because their system didn't initially want to do it. We had a file folder (and later a box) in our bedroom, and every time something with our name and address came through, we threw it in the box for sorting and ordering at a later date.