Companion voucher return Jan ’24, can I book outbound now return later?

[ExpatInBerlin]

Apologies if this is a silly question.

I have an old style companion voucher expiring Feb ’24 and am looking to book a return trip from LHR to YVR in Jan ’24. At present, we know our departure date and there are seats available in Economy (which we’re happy with) so are keen to get the outbound leg locked in. However, we are flexible on our return date by several days and would be keen to leave it a little while longer to book this in as we are only a few thousand avios away from being able to book this in PE rather than economy.

My question is, is it possible to book this either online/on the phone to BA as a one way companion voucher trip now and then add the return leg at a later date? I know people do this when flights have just been releaed at mindnight 355 days before to lock in coveted club seats, but is it still fine to do it when the return flights are already available to book online?

Also, where do YVR flights rank on the popularity scale in terms of likelihood for all reward seats to get booked out soon? Thanks.

[tiriavpo]

Maybe – your biggest issue might be that YVR is a popular route and if you wait, the economy seats might go in the meantime. If you book economy now, and PE seats become (or remain) available, and you amass enough avios, you can change cabin later – albeit for £35 per person change fee.