FWB / Cargo-IMP Validator: catch airline FNA rejections instantly
Paste an FWB or Cargo-IMP message to see exactly what an airline will reject — and how to fix it.
AWB Studio is the full air-waybill workspace — create, validate, label, price & send. Start free.
What the validator checks
Checked against IATA Cargo-IMP FWB/17 rules — the same ruleset airline cargo systems apply before they accept a booking. Every mandatory block is inspected: if any field is missing, malformed, or out of range, the airline will return an FNA (Freight Not Accepted) and the booking stalls until you correct and retransmit.
AWB mod-7 check digit
The 8th digit of the AWB serial must pass a mod-7 calculation. A transposed or copied digit fails this check immediately.
Shipper & consignee blocks
Both SHP and CNE blocks must include name, full street address, city, and country. Trailing spaces and missing fields trigger an FNA.
Routing codes
Airport, airline, and country codes are validated against IATA reference tables. A single wrong character — "LHN" vs "LHR" — returns an FNA.
Charges & currency
Declared charges, charge mode (prepaid vs collect), and currency codes must be internally consistent and within valid ranges.
Special-handling codes
Required SHC codes for dangerous goods and temperature-sensitive cargo must be present and correctly formed.
Charset & field length
IATA Cargo-IMP permits only specific ASCII characters per block. Accented characters, tabs, or overlong fields cause silent truncation or rejection.
The tool also flags common formatting problems: trailing spaces in the shipper block, incorrect two-letter carrier codes, invalid country or airport codes, charge mode conflicts (prepaid vs collect on the same line), and missing special-handling codes for dangerous goods. These are the issues that generate the most FNA traffic on the network — catching them here saves a round trip to the airline. AWB Studio shows each error in plain English — the field, the rule it breaks, and the fix — before the airline ever sees the message.
Common FNA rejection reasons
Most FNA rejections fall into a handful of categories that repeat across forwarders and airlines.
The CNE block must include name, full street address, city, and country. A PO Box without a street address is insufficient on most carriers.
How to fix a missing consignee FNAThe 8th digit of the AWB serial must pass a mod-7 calculation against the 7-digit serial. A transposed digit or a copied number fails this check immediately.
How to fix an AWB check digit rejectionAirlines require the shipper name, address, and country in the SHP block. Leaving the city or postal code blank triggers an FNA on most carriers even when the rest of the message is correct.
Declaring both prepaid and collect charges for the same line (e.g., freight prepaid but OtherCharges collect without a valid charge-mode indicator) causes automated rejection.
Airport, airline, and country codes must match IATA reference tables exactly. A single wrong character returns an FNA; "LHN" instead of "LHR" is enough.
How to fix errors
Each finding tells you the block name, the field that failed, and the rule it broke. Fix the source data then paste the corrected message back and rerun. Repeat until the validator returns no errors, then transmit to the airline.
- Paste your FWB
Copy the full FWB message from your cargo system or email and paste it into the validator above.
- Read the findings
Each error shows the block name (e.g., "CNE"), the field that failed (e.g., "city"), and the rule it broke (e.g., "required field missing").
- Fix the source data
Correct the issue in your shipment record or directly in the FWB text. For check-digit errors, use the AWB check digit calculator to recompute the correct 8th digit.
- Re-run the validator
Paste the corrected message back in and rerun. Repeat until the validator returns no errors.
- Transmit to the airline
A clean run here means the airline cargo system will accept the booking on the first attempt — no FNA round-trip.
For systematic fixes — especially recurring check-digit errors — use the AWB check digit calculator to recompute the correct 8th digit before editing the FWB. For deeper context on any rejection, the learn articles explain each FNA reason and its fix in detail.
Ready to create air waybills that get accepted the first time?
AWB Studio creates MAWB & HAWB documents, generates FWB/FHL Cargo-IMP messages, and runs the same FNA validator live as you type. Open self-serve — no invite, no salesperson. Free tier includes the validator and 5 documents per month.