Yesterday I wrote that British Airways, Iberia, and Avios would be launching a 25% off award sale valid on long haul routes.

Details of the sale are now online.

As I expected, the terms and conditions specify “Flights depart London” and that led me to believe the 25% discount would be available only on London-originating itineraries.

One Mile at a Time beat me to the punch with the word that 25% will actually come off of all long haul award flights to and from London.

The sale is on for six days only and permits travel through the end of May in any class of service. This is a discount on the mileage cost of the award only and not on taxes and fuel surcharges (which, route-depending, can be substantial). Partner flights aren’t eligible, it’s valid on British Airways and Iberia only. But if you have a companion award ticket (from spending $30,000 on the Chase British Airways Visa) you can combine the mileage discount with the companion award.

Which means that a US-originating one-way or roundtrip gets the discount.

And, say, Los Angeles – London – Johannesburg gets the discount on the entire journey.

The only thing that isn’t discounted, it seems, would be short-haul segments. You can include those in your award, but since Avios prices each segment separately (except that UK domestic connections are a throw-in on international award itineraries) the discount applies only to the long haul segments.

You can, of course, top off an Avios account with Chase or American Express points, both of which tend to transfer instantly (some programs like Starwood Preferred Guest take longer to transfer and you may not have points in your account in time to take advantage of this offer).

Before you transfer keep in mind that the Avios award chart — especially for premium cabin and long-haul routes — may be more than 25% above the mileage cost of competing programs under normal circumstances. I wouldn’t, say, transfer points to do more than top off a modest number of points for a given award. But for folks with Avios points already this is quite a good deal. And for folks with Avios bookings it may make sense to check whether there’s still additional award space on those same flights, because cancelling and rebooking for the points savings could make sense (but again — only if there is already still award space, cancelling an existing award does not guarantee that the seats go back into award inventory).