This seems like a development to counter the aa.com guarantee; doesn't apply in Europe though, alas.

How it is to be tested when no fare code is shown on ba.com, I am not sure.


Our Best Fares are at ba.com - Guaranteed!

When looking for the best British Airways fares online, you can rest assured that you’ll find our lowest fares at ba.com - guaranteed. If you find the same British Airways flight you’ve purchased on ba.com on another website, we’ll refund the difference*. Simply file a claim using the form below.

Not only does booking your British Airways flights at ba.com guarantee you our best fares, but it also makes the rest of your travel experience easier:


ba.com bookings incur no service fees or processing fees.

Plan and book your entire journey online including flights, hotels and car hire.

Manage your booking and select your seat using our interactive seat maps.

Even find ways to save time at the airport, including on-line check-in.


Terms and Conditions:
* Booking and full payment for a round trip originating in the United States must have been made at ba.com using a credit card with a US billing address. The Lower Online Fare must be for the exact same flights, on the same dates for travel, in the same cabins, have the same fare rules and restrictions as the British Airways itinerary purchased through ba.com and be sold in the US over the internet. Fares must include all taxes, fees, and surcharges.
Purchase at ba.com must be the least expensive option for the chosen itinerary available on ba.com at the time of purchase. Lowest Online Fare Guarantee applies only to itineraries that consist entirely of flights with a British Airways flight prefix (BA). Claims will only be accepted using the online claim form.


https://www.britishairways.com/trave...source=rh1_bfg