2 for the price of 1.

BA Premium Plus American Express card issues you with a 2-4-1 voucher if you spend over £10k per year. I have used this card for 6 years and I have received this voucher each year.

When using the voucher, BA will provide you with an additional ticket for the cabin class that you choose to fly in. Note that you can only use these vouchers when booking with miles. In addition, BA will still charge you the taxes on the flight. This means that economy flights to the US are around £375 and Australia is £650.

Normally, it makes more sense to use these vouchers in Clubworld or First.