BA's Advance Booking Curve Revealed
A recent flight cancellation gives us a rare glimpse of BA’s forward bookings on the Hong Kong route
Understanding advance bookings is one of the keys to airline revenue management. And when it comes to all-things top secret in aviation, it does not get more sensitive than this.
Airlines will tell us through the Global Distribution System when there are only a few seats left for sale. But the extent to which they are 25%, 50% or 75% booked up is known only to their pricing wonks.
Around Wed 17-Jul this year, BA cancelled one of their two Hong Kong services for the winter schedule, effective Sun 27-Oct. This is interesting for four reasons:
1. Cancelling a longhaul flight at this short notice is unusual and has given passengers a long time to book
2. Because there were two flights and now one, I would expect most passengers to have been automatically re-accommodated on the remaining flight
3. Since the flight is longhaul, large aircraft and fancy seats are involved, nicely segmented into four cabins
4. I had been studying these flights preparing to buy my own ticket to Hong Kong, so I know how things looked beforehand.
Before the cancellation inventory was wide open. Think something like:
F4 A2 J9 C9 D9 R9 I7 W9 E9 T3 Y9 B9 …
That is meaningless for knowing how many seats are left in any cabin except First, where there are only eight seats.
After the cancellation things changed. It went to something more like:
F4 A2 J7 C3 D2 R1 I0 W3 E0 T0 Y4 B0 …
We know or can reasonably assume four things:
1. The inventory availability fell to less than 9 on many cabins on many flights
2. Thousands of people did not book London to Hong Kong services between 16-Jul and 18-Jul
3. Since the flights are so far out whizzy overbooking algorithms have probably not taken effect yet
4. Before the cancellation one flight a day was a four-cabin 787-9 and the other a three-cabin 787-8, while afterwards it is a four-cabin 787-9 for the winter season and three-cabin 777-200ER for the summer season.
This means that we know:
1. The capacity before the change
2. The capacity after the change
3. How many seats are left on up to 72 flights to Hong Kong and up to 99 flights from Hong Kong
(3) divided by (2) tells us the seats sold as a proportion of post-change capacity, which will be much higher than normal.
(3) divided by (1) tells us the seats sold as a proportion of total pre-change capacity. That is their top-secret advance booking curve!
Now read on. Let’s check out the interesting results…
A few preliminary notes
I collected inventory availability on afternoon Sat-20-Jul, for the whole year. This is late enough for the auto-rebooking to have happened but early enough that most affected passengers will probably not have called BA yet to make a change. I think it is probably a good representation of how things stood at the time of cancellation.
The last date that anything interesting happened was 21-Apr-25. It is all wide-open-nines-across-the-board after that.
There are some charts showing raw inventory statistics and raw seats sold in an appendix at the end of this article. I wanted to get straight to the results.
World Traveller Plus
First of all, let’s look at World Traveller Plus premium economy.
Old capacity: 64 seats per day each way (PDEW)
New capacity:
39 seats PDEW (winter, 106 days)
25 seats PDEW (winter, 49 days)
40 seats PDEW (summer, 102 days)
The chart below shows the seats sold as a percentage of capacity. A blank space does not mean they did not sell anything, it means that inventory was showing W9 so we cannot tell how many seats are left.
Zoom in and stare a while at the charts, it is worth it!
Between the end of October and Sun-5-Jan-25, BA sold AT LEAST 60.9% of their (old) capacity on 16 out 72 days (22.2%) to Hong Kong and an impressive 45 out of 71 days (63.4%) from Hong Kong.
These numbers plateau out on the chart because there are no more seats left. Given how many high-scoring instances there are, the true bookings might be significantly higher and a good few lucky people might be in line for an upgrade to Club World.
They sold AT LEAST 50% of (old) capacity on 39 days out of London and 56 from Hong Kong.
But the advance bookings for this cabin do not stop in January. There is impressive heavy booking of World Traveller Plus all the way into April. 12 out of 106 eastbound services are at more than 33% (old capacity) booked and 23 westbound services.
It is interesting that there are many more heavily booked flights in World Traveller Plus from Hong Kong rather than two Hong Kong.
Since we would expect most people to fly both ways in the same cabin, demand seems to be more concentrated westbound and more spread out eastbound.
Finally, take a look at what happens around Christmas. Flights into Hong Kong are not currently constrained only on the four days 23- to 27-Dec, but flights from Hong Kong are not constrained for a much longer period, 22-Dec to 30-Dec. The other way round to what we found before.
Here is what I found for advance bookings by day of the week, until 5-Jan.
To Hong Kong:
Mon: 60% constrained (flights after the capacity reduction are nearly fully booked)
Tue: 40% constrained
Wed: 50% constrained
Thu: 50% constrained
Fri: 80% constrained
Sat: 81.8% constrained
Sun: 54.5% constrained
From Hong Kong:
Mon: 70% constrained
Tue: 80% constrained
Wed: 90% constrained
Thu: 90% constrained
Fri: 90% constrained
Sat: 81.8% constrained
Sun: 72.3% constrained
Conclusion: It is well known that premium economy is a hot seller. For BA in this route, it is a hot seller some way in advance. This does not mean that the yields are amazing though, after all they have just pulled half the flights…
Avios collectors might need to be more flexible on dates flying from Hong Kong and might have more choice of dates to Hong Kong. Except at Christmas when it might be the other way round… They should avoid Sat on the way to Hong Kong but might have better luck on Sat, Sun, Mon and Tue on the way to London.
Club World
Now let’s move forward to snazzy Club World business class with it’s fabulous flat beds.
Old capacity: 77 seats per day each way (PDEW)
New capacity:
42 seats PDEW (winter, 106 days)
35 seats PDEW (winter, 49 days)
48 seats PDEW (summer, 102 days)
Club is currently constrained (less than nine seats available) on 36 flights to Hong Kong and 38 flights from Hong Kong.
Zoom in and stare a while at the charts, it is worth it!
Between 26-Oct and 5-Jan more than one third of seats based on the old capacity had been sold on 43 out of 72 days (59.7%) to Hong Kong and 25 out of 71 days (35.2%) from Hong Kong.
More than half of the seats at old capacity were sold on 39 days ex London and only eight days ex Hong Kong.
Flights into Hong Kong are not currently constrained only on the four days 23- to 27-Dec, but flights from Hong Kong are not constrained for a much longer period, 22-Dec to 30-Dec. The same pattern that we saw in World Traveller Plus.
Here is what I found for advance bookings by day of the weekk, until 5-Jan.
To Hong Kong:
Mon: 10% constrained (flights after the capacity reduction are nearly fully booked)
Tue: 30% constrained
Wed: 40% constrained
Thu: 40% constrained
Fri: 60% constrained
Sat: 45.5% constrained
Sun: 36.4% constrained
From Hong Kong:
Mon: 40% constrained
Tue: 40% constrained
Wed: 10% constrained
Thu: 20% constrained
Fri: 50% constrained
Sat: 45.5% constrained
Sun: 36.6% constrained
Avios collectors might need to more flexible on dates flying to Hong Kong and might have more choice of dates from Hong Kong. They might have good luck considering Mon to Thu to and from Hong Kong, and especially Wed or Thu from Hong Kong.
First
Turning our attention to swanky First, which delivers an extra slug of space, privacy and comfort over Club.
Old capacity: 8 seats per day each way (PDEW)
New capacity:
8 seats PDEW (winter, 106 days)
Zero seats (winter, 49 days)
Zero seats (summer, 102 days)
The loss of First on Hong Kong is a game-changer. Out of all BA’s routes, this is the one where in years gone by this cabin would have been expected to go out rammed. Tempora mutantur.
Zoom in and stare a while at the charts, it is worth it!
Although capacity has not changed, I was quite surprised to see just how far in advance First is booked up. The cabin is already sold out on six days in each direction. Only one or two seats are available on 20 days to Hong Kong and 16 days from Hong Kong.
For a cabin that is traditionally associated with last-minute-bookin’, high-fare-payin’, city-slickin’ business leaders this is surprising. An interesting subject for another article…
If anything can be said about the days which are less or more heavily booked, it is that on the way to Hong Kong, 70% of Mon flights are currently less than 50% booked while 80% of Fri flights are currently more than 50% booked.
On the way back to London, Wed may be subject to slightly less advance booking, with 80% of flights currently less than 50% booked.
All that said, I would expect most First cabins to go out full.
Avios collectors will always be lucky to get seats in this cabin on Hong Kong or any other route. I did it quite easily when there were 14-First seat A380s and 777s plying the route double-daily. But now there is almost no chance.
World Traveller
Old capacity: 281 seats per day each way (PDEW)
New capacity:
127 seats PDEW (winter, 106 days)
154 seats PDEW (winter, 49 days)
184 seats PDEW (summer, 102 days)
Note how the physically smaller 787-8 has more economy seats than the larger 787-9, which is stacked with plusher seats.
Zoom in and stare a while at the charts, it is worth it!
Even World Traveller with it’s hundreds of daily seats gets booked up early. There are clusters around Christmas and things look busy into London late in October.
It is Fridays and Saturdays where bookings seem to be coming in fastest. On the way to Hong Kong 60% of flights are currently unconstrained on these days while on other days it is 70% to 90% unconstrained. On the way back, Friday seems to full up fastest with only 40% of flights unconstrained.
Avios collectors looking to redeem in World Traveller normally have a good choice. Not so on Hong Kong.
Availability in the October to Jan period is patchy. For instance there are no Avios flights at all into Hong Kong in October and only one out in November.
To be honest, I expect the limited Avios availability to go away in World Traveller. It is probably more a symptom of the cancellation. In 2025 so far, seats are available on most days. At the time of writing there is excellent availability from Feb-25 except around Easter.
Appendix
Here are the charts showing inventory availability out of 9 when I collected the data on Sat-20-Jun. Zoom in and stare a while at the charts, it is worth it!
Here are the charts showing number of seats sold when I collected the data on Sat-20-Jun. Zoom in and stare a while at the charts, it is worth it!
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