Apparently Qantas is changing this to allow multiple bookings from a credit voucher.Yes you can, as long as the new fare amount is equal to or higher than the original fare amount (i.e. the new fare is more expensive than the old).
$1.5m ‘Noah’s Ark’ flight to get pets home — Herald Sun
Americans who were forced to leave Australia after COVID-19 claimed their jobs and visas could fork out $1.5 million for a Noah’s Ark-style charter flight to get their pets home.
apple.news
“This provides more flexibility in how these vouchers are used.
“A customer could use the travel credit from a cancelled flight to London to instead go on several interstate holidays over the next 18 months or so.