D83, X83, D84 and X84: understand the GAEB formats

Different files for the same construction project

You may receive a D83 and be asked to return D84, or see X83 and X84 in another tender. The number identifies the exchange phase and the letter the format family. These are not merely different filenames for identical content.

Phase 83 is the invitation to tender; phase 84 is the offer return. D83 uses GAEB 1990; X83 uses the XML family. The official GAEB FAQ explains extensions and exchange phases.

File	Family	Typical role
D83	GAEB 90	Tender source for pricing
X83	GAEB DA XML	XML invitation to tender
D84	GAEB 90	Structured offer return
X84	GAEB DA XML	XML offer return

The official GAEB DA XML 3.3 package includes the relevant XML phases. Confirm the actual version and return format in the tender documents or with the issuer.

Why a return may not look like the whole bill

Hassolux offer returns contain prices associated with item references, or OZ, and designated bidder text fields. For supported D83 notes, validation may explain that the text remains in the original and readable PDF without being repeated in the price return.

An empty description column in a viewer does not by itself prove missing prices. Check which file is displayed and whether the viewer processes it alongside the original source. Compare references, unit prices and totals. Missing values or mandatory bidder answers are a specific issue to resolve.

Keep the original tender as the basis for descriptions, quantities and mapping. A filled PDF can complement the offer but cannot replace a required native return.

Treat conversion as a separate decision

GAEB 90 is line-oriented; XML uses elements. Conversion can preserve only content represented by the destination format, as the GAEB FAQ explains. Renaming D83 does not produce valid XML.

Choose the target format and read its messages. If D83 is converted to X84, the recipient must accept that format and item mapping. A newer format does not guarantee every older source can be converted without limitations.

Review the actual output

Save and validate after edits. Resolve errors, read warnings and check source references and required responses. A warning acknowledgement is not a correction. Downloading neither submits an offer nor creates an order.

Use the GAEB guide, read the bill and, for materials, prepare supplier enquiries.