How the codes are grouped
| Codes | Area |
|---|---|
| 00–09 | Internal airline use (00–05 airline-defined; 06–09 cover gate availability, connections and short ground time) |
| 11–19 | Passengers and baggage |
| 21–29 | Cargo and mail |
| 31–39 | Aircraft and ramp handling |
| 41–48 | Technical and aircraft equipment |
| 51–58 | Damage to aircraft and system failures |
| 61–69 | Flight operations and crew |
| 71–77 | Weather |
| 81–89 | Air traffic control and airport or government authorities |
| 91–96 | Reactionary (caused by an earlier delay) |
| 97–99 | Industrial action and miscellaneous |
The authoritative list is the current edition of IATA’s Airport Handling Manual. Codes are sent in aircraft movement messages, where the numeric form is used.
How airlines use them
- Finding root causes: grouping delays by code shows which areas — handling, technical, crew, air traffic control — cost the most minutes.
- Separating knock-on delays: reactionary codes show how much delay is inherited from earlier flights rather than created on the spot.
- Accountability: codes assign each delay to a department or partner, such as a ground handler or the airport.
- Improving OTP: targeting the codes behind the most delay minutes is the most direct way to improve punctuality.
Delay codes in Wireum Insights
Wireum Insights breaks delays down by IATA delay code, shows how delays propagate through later flights, and attributes them by department, next to on-time performance and IROPS.