Using a Gold Upgrade voucher with an Amex 2-4-1 voucher
You can combine a GUF with a companion voucher (also known as a 2-4-1). This is a great way to really get a really good value use for the voucher as you will save a very large amount of Avios.
For example, a pair of F off-peak reward seats LHR-SYD rtn would set you back a total of 680,000 Avios for two without a companion voucher, and 340,000 Avios with a companion voucher. Instead you can use your companion voucher to effectively book a pair of CW reward seats (250,000 Avios total off-peak for two for a return) and then also apply your GUF to go in to F which will cost no extra Avios. Your combined use of a GUF and a companion voucher have therefore saved you a total of 680,000-250,000 = 430,000 Avios
2 weeks ago I cancelled a flight to South America booked using a GUF1 and an AMEX 2-4-1. I told the agent that I wanted to reschedule but he advised me to cancel and make a new booking. My account was quickly updated with 65K Avios and the 2 vouchers (but as yet no refund for the taxes, but that's another issue).
I had managed to get new outbound leg tickets using the AMEX 2-4-1 for 85K (?) and phoned up the GGL line as I noticed return tickets had become available. I was told that I could NOT use a GUF1 with an AMEX 2-4-1 voucher and was asked for another 125K Avios. I asked the agent to check this as I had used these vouchers together in the past and in the cancelled booking.
She told me that (in no uncertain terms !) that she was correct and had 'never utilised both vouchers in a booking in all the years I have worked here'. I asked her to look at the cancelled booking which she did, but then told me that booking was made in error. She is adamant that to book a 2 new off-peak J return flights to SCL is 250K even using the AMEX 2-4-1 and I cannot use the GUF1
If only I had not agreed to cancel the previous booking !!!
agent is right guf2 can be used with 241 but not guf1 you got lucky first time with an agent error