FHL vs FZB: what's the difference?

The consolidation problem

A consolidation exists because one forwarder can combine cargo from many shippers under a single master air waybill (MAWB) — the contract between the forwarder and the airline, covering the whole shipment airport to airport. Underneath that one MAWB sit multiple house air waybills (HAWBs), each issued by the forwarder to one of the individual shippers whose goods are riding inside the consolidation. Two different Cargo-IMP messages exist because two different questions need answering: which house waybills are in this consolidation, and what does each one actually contain?

FHL: the consolidation list

FHL stands for Consolidation List — its Standard Message Identifier is literally FHL. Per the Cargo-IMP manual’s own message function statement, its primary job is “to provide a ‘Check-list’ of House Waybills associated with a Master Air Waybill,” with an optional second function “to provide details of House Waybill consignments.” It is a computer-to-computer message sent from the access address of the cargo control computer of the forwarder responsible for the master AWB to the access address of the cargo control computer of the airline handling that master AWB.

Structurally, an FHL opens with the Standard Message Identification, then a Master AWB Consignment Detail block (in the manual’s own examples, this line begins MBI/ and carries the master AWB’s airline prefix, serial number, origin/destination, and quantity), followed by one House Waybill Summary Details block per house waybill (the example line begins HBS/ and carries the HWB serial number — up to 12 characters — its own origin/destination, its totals (pieces, weight code, weight, and optionally SLAC), and a Manifest Description of Goods). Optional blocks can add free-text goods descriptions, Harmonised Tariff Schedule commodity codes, and “Other Customs, Security and Regulatory Control Information” carrying an ISO country code. That optionality is the key point: FHL can carry customs and commodity-code detail, but nothing in its core structure guarantees the full shipper, consignee, and rate detail of each house waybill — that detail is explicitly flagged as an optional extra.

FZB: house waybill data

FZB stands for House Waybill Data — Standard Message Identifier FZB. Its message function is a single, unambiguous line: “To transmit a complete set of House Waybill Data.” Unlike FHL, FZB isn’t limited to a forwarder-to-airline exchange: the spec defines both From and To as “the access address of the cargo control computer of a participant involved in the movement of a consignment” — any party in the chain. Per the manual’s Message Use note, “FZB Messages will be sent either automatically at a dedicated time or as an answer to a FZA message.”

An FZB opens with Message Standard Identification, then an HWB Consignment Details block (the manual’s own example line begins HCD/ and carries both the MWB identification — airline prefix and AWB serial number — and the HWB identification for the specific house waybill). From there, the manual’s worked examples show it layering on the same kind of detail an FWB carries at the master level, but for one house waybill: a Shipper (SHP) and Consignee (CNE) block with name, address, and location; an Agent (AGT) block; Routing (RTG); a currency and valuation declaration (CVD); a rate description (RTD) carrying the nature-of-goods text; other charges (OTH) and a prepaid charge summary (PPD); a certification (CER) signature; issuing details (ISU); and, where relevant, a Special Service Request (SSR) free-text line, a Notify Party (NFY), and a House Awb Holder (HAH) block. Long FZBs can be split across multiple messages, closing each part but the last with PART/n/CONT and the final one with PART/n/LAST.

Side-by-side

	FHL — Consolidation List	FZB — House Waybill Data
Message function	”Check-list” of house waybills under a master AWB, plus optional consignment detail	”A complete set of House Waybill Data”
From	Forwarder’s cargo control computer responsible for the master AWB	Any participant’s cargo control computer involved in the shipment
To	Airline’s cargo control computer handling the master AWB	Any participant’s cargo control computer involved in the shipment
When sent	Message use not further specified beyond the above exchange parties	”Automatically at a dedicated time” or “as an answer to a FZA message”
Core content	One summary line per house waybill: HWB serial number, origin/destination, pieces, weight, nature of goods	Shipper, consignee, agent, routing, rate description, charges, certification — for one house waybill
Shipper/consignee detail	Optional (“(optional) To provide details of House Waybill consignments”)	Core to the message’s stated function
Example line identifier	MBI (master AWB line), HBS (house waybill summary line)	HCD (house waybill consignment detail line)

Why it matters

The two messages carry genuinely different data, so which one a system reads determines what it can actually see. An FHL check-list gives you the roster of house waybills in a consolidation — serial numbers, weights, piece counts, and a manifest description of goods — plus, optionally, tariff codes and a country code under its Harmonised Tariff Schedule and “Other Customs, Security and Regulatory Control Information” elements. What it doesn’t guarantee is the complete commercial picture of any single house waybill: shipper and consignee detail there is explicitly optional. FZB is the message whose stated, unconditional job is that complete picture — shipper, consignee, agent, and rate description for one house waybill in full. A system that only ever ingests FHL and assumes it’s getting “house waybill data” will be missing exactly the fields FZB exists to carry.

How Flaks handles FHL and FZB

Flaks generates and parses both messages as part of the same Cargo-IMP stack that handles the master FWB: the consolidation check-list (FHL) and the full house-level detail (FZB) for every house waybill inside it, without anyone re-keying data that already exists in one message or the other. See the API overview.