I have been watching one number for a year now and it barely moves.

ARC publishes the share of US agency transactions settled through NDC. It was 21.4% in May 2025. It was 21.6% in May 2026. Still 21.6% in June.

Twelve months, twenty basis points.

Chart: NDC share of US agency air transactions, flat from 21.4% in May 2025 to 21.6% in June 2026, while US agency air sales grew 12% over the same period

What makes it interesting to me is that the market itself grew. US agency air sales were up 12% in the first half, to $58.8bn. So NDC volume went up. The share did not.

You also see numbers like corporate NDC bookings up 168% year on year. I think both are true. They are measuring different things. One is a segment growing quickly from a small base, the other is the whole market.

I do not have a clean answer for why it flattened here. My own feeling is that it has less to do with standards and more to do with what happens after the booking, and I will come back to that in a few weeks. The NDC chapter of Airline Distribution Explained works through that servicing gap and what it costs.

Curious what others are seeing. A plateau, or just a pause?

What I left out

The number is US agency transactions only, from one reporting body. It says nothing about direct channels, about Europe or about Asia, and I framed it as if it described the whole picture.

Share is also not volume. US agency air sales grew 12% in the first half, so NDC volume went up while the share stood still. Both readings are true and they support different arguments.

Three months later I would lead on servicing rather than on the share, and use this number as the supporting evidence rather than the headline.

Sources

The ARC share figure is published monthly. It was current when this was written.