Confusion using upgrade voucher

[Wavey_dave_76]

I am trying to look at using by upgrade voucher and the ba site is confusing me on how these actually work.

Doing a search for availability, using the “book with avios” option, I can not see any option to use the voucher. It does appear under the “book and upgrade with avios” option, but when I select it there and do a search the options come back with the cash price for the flight, taxes etc, and the avios needed to upgrade (looks like if I hadn’t even got the voucher).

This has confused me on two fronts. Firstly, because I can’t understand how the voucher is supposed to be applied, but secondly because it makes me doubt my understanding of how these work. It was my understanding that they can only be used when avios is used to fully pay the flights… so why is the option under the “buy and upgrade” tab anyway.

FWIW I am only looking at various flights at the moment. I have my second voucher dropping in a couple of months so will book something when we can fly club both ways. I know I am going to have to ring to actually book using 2 vouchers anyway, and for now was just looking at full redemption and halving the cost in avios to see what it costs, but if I have misunderstood how this works, I could do with knowing sooner rather than later.

[Flyer123]

It can be used under the Book and upgrade option, select Economy/Premium Economy, which is the “pre-booking” class, so it will automatically check for Premium Economy/Business respectively.
Once this is done, it shows a pop-up asking which voucher to select – All your eligible vouchers with end-dates are displayed there and one of it can be selected to check the pricing. It will then show the actual cost of miles and surcharges/taxes on the next screen.