Originally Posted by
MPH1980
AFAIK - no - avios bookings become unchangable and uncancellable within 24 hours of the first flight.
Hence why it's better to do 2 one-ways than a return with avios unless you need to use a 2-4-1 or a GUF2/1 - because you get full control over both flights until 24 hours before each flight.
Changes to Avios redemptions can be made up 24hrs before each sector.
Cancellation for Avios re deposit is still 24hr before first sector.