From the FAQ of the Canadian Embassy in Austria:
I do not have a return ticket. Can I travel to Canada with a one-way
ticket?We strongly recommend that travellers who enter as tourists present a
return ticket upon entry into Canada, but this is not a legal
requirement. Port of Entry officers may want to see proof that the
person entering Canada will leave before expiry of their authorized
period of stay.If you are the holder of a work or study permit, you generally do not
need a return ticket. At the port of entry in Canada you might have to
prove that you are able to fund your return flight.
If I was a customs officer and I saw one person has a visa to stay, and the other does not but bought a one way ticket I would most certainly assume that person planned to stay. And in fact, she does. Don’t start your time here with a lie. Call whoever is processing her visa and ask what to do. She may have to change her flights and stay back until the paperwork comes through. While this is irritating, it sure beats the alternative.
If she tries going without the right visa, it might just work. But you might instead find:
Compared to these choices, her staying back for a week or two seems like a much safer option. But followup with whoever is issuing it – maybe it will arrive just in time, or you can speed things up by travelling somewhere in the next few days to pick it up.
Actually your first concern will be the airline, as rules require them to make sure you have the correct documentation to enter Canada BEFORE they let you on the plane. It is entirely possible that they could prohibit your girlfriend from flying.
Once you get to Canada, it is a crap shoot, they may simply take her word that she is visiting only for a few weeks or they could ask about her return flight.
If you haven’t bought your tickets, you could buy a round trip for her (which often cost the same as a one way), which will satisfy the immigration rules and then postpone the return date or simply cancel it.
Credit:stackoverflow.com‘