Where to find my Companion Voucher / use on partner airlines?

[Zed]

Amex tells me I have earned my Premium Plus Companion voucher.
Where does this show up for me for use on the BA website?
Also, can this be used on Partner Airlines such as Qatar Airways?

[Froggee]

If you log into your Executive Club account and click on your name in the top right then it opens your Executive Club page and you should see your eVouchers listed about halfway down.

Failing that, start making an Avios redemption and any vouchers you have will be shown.

Voucher only good with BA

[NorthernLass]

You can redeem by selecting “Book a flight with avios” – it will come up as the default option, so you have to actively unselect it if you are booking for one person. BA-operated flights only, but with the new-style vouchers you don’t have to depart from the UK any more, which can save some money in surcharges.