Originally Posted by
Cap'n Benj
I've done this a number of times. You can either complete the booking online and call to MFU, or complete the whole process over the phone.
I have never been charged an offline fee, both as a Blue or Silver, simply state to the agent that you are unable to do it online.
It's a lottery. What you described used to be the case, now it depends very much on the agent you happen to get, though my experience is it's a minority of cases where you don't get charged because ba.com doesn't support the feature.