@Leon93 I don't have an answer but more of a follow-up related question.
We are looking at using a separate, over the garage unit as Airbnb next year. We have gone through permits and inspections too late to rent this year. But have a few questions/comments
We appear to be in the same situation.
We are non-Canadian residents with property in Canada. Originally from Canada but now living in US. We also have a long term rental so have experience dealing with Canada Revenue Agency (CRA) although not with respect to GST.
1) as full time rental, we had to remit 25% of gross rental to CRA on monthly basis.
Typically, we got back 95% when we filed a Non-Resident (NR) return
Since we are covered by Canada-US Tax treaty, we can only be taxed by country in which we reside. Dont'y know if there is a Canada-UK Tax Treaty
2) If you rent for more then 89 days you are considered a commercial operation which appears to be a Pandora's box. If you had GST in excess ok $30k that means income of $200k +/-.
3) If you are over $30k in GST, would suggest contacting a an accountant that specializes in this. We have an accountant for normal NR return but she does not want to handle us for Airbnb issues - so we are in same boat.
4) Also, as non-resident owner, look into the new (2023) Underused Housing Tax (UHT), a federal 1% tax on the ownership of vacant or underused housing in Canada that took effect on January 1, 2022. I'll let you Google that but source is government website cananda.ca. There are exemptions but major impact is not filing - $5,000 penalty. We met 2 of exemptions and so no tax.
Are there any Canadian, non-resident hosts, that have any advise - maybe condo owners in Toronto, Montreal, Vancouver- on taxation?