Originally Posted by
umichguy
When you log into your BAEC (personal) account, on the left you should be able to see the option of book with Avios or Money. Select the "book with money, upgrade with Avios" option". And below you can select which cabin you want to upgrade from and on which leg (s).
I was talking about On Buisiness account, but thanks anyway.
Looks like having a BA Business account is a waste of time