A practical guide for travel agents on fixing the COMBINATION NOT ALLOWED [TTP] error in Amadeus when the ticketing options you enter conflict with the TST or PNR structure.
The COMBINATION NOT ALLOWED [TTP] error is one of the most frequent ticket issuance errors in Amadeus. It appears when an agent tries to issue a ticket using the TTP command, but the ticketing options entered do not match the structure of the PNR or the TST. The system rejects the request because the combination of elements โ passenger, segment, TST number, or Passenger Type Code โ cannot be processed together. This article explains the exact cause of the error and gives you the correct TTP entries to use instead, so you can issue the ticket without delay.
Why the โCombination Not Allowedโ Error Happens
This error occurs when the options you add to the TTP command are not combinable. Common situations include:
- Combining a TST number with a passenger or segment number in a way that conflicts.
- Mixing a Passenger Type Code (PTC) that does not match the PTC stored in the TST.
- Trying to issue multiple tickets at once when only one ticket can be reissued or exchanged at a time.
- Using TTP options that do not reflect the correct segments for a partially flown itinerary.
Solution: Use the Correct TTP Combination
Step 1: Check that your TTP options are combinable
Review the options you are adding to TTP. Do not mix TST number and passenger/segment associations in a way that conflicts with each other.
Step 2: Choose one valid approach
Use the TST number on its own:
TTP/T3/RTOr use the passenger and segment association:
TTP/P2/S3-4/RTStep 3: Match the ticketing options to the TST
Verify that the Passenger Type Code (PTC) used in your entry matches the PTC stored in the TST. A mismatch between adult, child, or infant codes will trigger the error.
Step 4: Handle partially flown itineraries correctly
For partially flown itineraries, you may need to include the TST number in the entry, for example:
TTP/T4Remember that only one ticket can be reissued or exchanged at a time. If you are reissuing, process each passenger separately.
Quick Fix Checklist
- Check the TTP options you entered and confirm they are combinable.
- Use either the TST number (
TTP/T3/RT) or a passenger/segment entry (TTP/P2/S3-4/RT). - Verify that the PTC in your entry matches the PTC in the TST.
- For partially flown itineraries, add the TST number to the entry.
- Reissue or exchange only one ticket at a time.
- Retry the TTP command and confirm successful issuance.
Frequently Asked Questions
What does โCOMBINATION NOT ALLOWED [TTP]โ mean?
It means the options you combined in the TTP command cannot be processed together by the system, so the ticket issuance is blocked.
Can I use the TST number and passenger number together?
Not in a conflicting way. Use either the TST number alone (TTP/T3/RT) or a passenger/segment association (TTP/P2/S3-4/RT).
Why does the error appear on partially flown itineraries?
Because the TST structure may require you to include the TST number in the entry, such as TTP/T4, and only one ticket can be reissued or exchanged at a time.
Conclusion
The COMBINATION NOT ALLOWED [TTP] error is not a system bug โ it is a signal that your ticketing options do not match the TST or PNR structure. By using either the TST number (TTP/T3/RT) or a passenger/segment entry (TTP/P2/S3-4/RT) โ and never both in a conflicting way โ you can issue tickets smoothly. Always confirm that the PTC matches the TST, include the TST number for partially flown itineraries, and process one ticket at a time when reissuing or exchanging.
Also Read:
CHECK PASSENGER ASSOCIATION
CHECK ITINERARY
CANCEL SEAT ITEM OR SPLIT PNR PRIOR TO NAME RE-ENTER
