TecDoc Explained: What It Is and How Automotive Parts Data Works

If you sell automotive spare parts in Europe, TecDoc is the database your fitment data ultimately traces back to. It is the industry-standard reference for which parts fit which vehicles, maintained by an industry consortium called TecAlliance, and used by virtually every parts distributor, data service, and aftermarket retailer in the European market.

Despite its centrality to the parts business, TecDoc is poorly understood outside of technical operations roles. This guide explains what TecDoc contains, how it is structured, how it is maintained, and what it means for spare parts sellers who want accurate catalog data.

What TecDoc actually contains

The TecDoc database is organized around two linked structures: the vehicle catalog and the parts catalog. The vehicle catalog lists every vehicle make, model, engine variant, and production year in a hierarchical structure. The parts catalog lists every part by category, brand, and part number. Fitment records link the two: a fitment record says "part X fits vehicle Y in position Z."

The vehicle catalog structure

TecDoc's vehicle catalog organizes vehicles in a four-level hierarchy: Make → Model → Type → Engine. Each level has a unique TecDoc ID. A Nissan Juke 1.6 DIG-T 190hp manufactured between 2013 and 2019 has a specific TecDoc Type ID that distinguishes it from the 1.2 DIG-T 115hp variant manufactured in the same period. Fitment records reference these Type IDs, which is why TecDoc fitment data can distinguish between engine-specific fitments that appear identical by make, model, and year alone.

The parts catalog structure

Parts in TecDoc are organized by Generic Article Group — a standardized part category classification. Brake discs, air filters, oil filters, spark plugs — each has a Generic Article Group code that is consistent across all manufacturers. Within a Generic Article Group, each IAM brand submits their parts with their own part numbers, technical attributes, and cross-references to OEM part numbers. This consistency across brands is what makes TecDoc cross-reference data reliable: the Generic Article Group enforces that you are comparing equivalent categories, not just equivalent part numbers.

How TecDoc cross-reference data works

Cross-reference data in TecDoc links IAM part numbers to OEM equivalents. When Bosch submits a brake disc to TecDoc, they include a reference to the OEM part number it is designed to replace. TecDoc stores this as a cross-reference record linking Bosch's part number to the OEM number.

This creates the multi-directional lookup that makes TecDoc useful. Starting from an OEM part number, you can retrieve all IAM equivalents. Starting from any IAM part number, you can retrieve the OEM original and all other equivalents. Starting from a vehicle, you can retrieve all compatible OEM part numbers and all their IAM equivalents in one query chain.

The limitation of TecDoc cross-reference data is that it depends on IAM brands submitting accurate references. Brands that have not formally submitted a cross-reference to TecDoc will not appear in the lookup, even if their part is physically identical to the OEM. Quality data providers supplement TecDoc cross-references with fitment-based equivalence matching to fill these gaps.

How TecDoc is maintained

TecAlliance members — IAM manufacturers and OEM brands — submit catalog updates quarterly. Each quarterly release is versioned and distributed to licensed TecDoc subscribers. The submission process has quality control requirements: parts must conform to the Generic Article Group attribute definitions, cross-references must be validated against OEM catalog data, and fitment records must reference valid TecDoc vehicle IDs.

This controlled submission process is why TecDoc data is more reliable than freely available parts information — it requires manufacturers to verify what they submit. But it also means TecDoc is never fully real-time. A new IAM part that is launched in January will not appear in TecDoc until the next quarterly release. Parts that are superseded midway through a quarter may temporarily show incorrect availability status.

TecDoc update cycle and data freshness

Quarterly updates mean data can be up to three months old at any point. For fast-moving categories like spark plugs and filters with frequent supersession cycles, this matters. For stable categories like structural body parts, quarterly updates are more than sufficient. The important practice is to sync your catalog data with each TecDoc quarterly release — accumulating multiple releases without updating creates progressively larger accuracy gaps.

Accessing TecDoc data as a spare parts seller

TecDoc data is not publicly available. Access requires a commercial license from TecAlliance, which involves contractual volume commitments and technical integration. For most spare parts businesses — particularly smaller and mid-size sellers — the direct TecDoc license is not the right path. The volume commitment is high, the integration is complex, and TecDoc's raw output requires significant processing before it is usable as product page content.

Using a data enrichment provider

Most spare parts sellers access TecDoc data through a licensed data enrichment provider. The provider holds the TecDoc license, processes the raw data, adds quality validation and confidence scoring, supplements TecDoc with additional sources where coverage is thin, and delivers the enriched output in formats designed for product page publication — including SEO metadata fields, year-by-year keyword expansions, and structured FAQ content.

This is the access model that makes sense at catalog scale: you submit part numbers, you receive publication-ready enriched data, and the data provider handles the TecDoc licensing, update cycles, and data quality management.

TecDoc and GEO: what AI search engines see

When AI search engines answer fitment questions — "what brake disc fits a 2015 Nissan Juke 1.6 DIG-T?" — they look for pages with specific, verifiable answers. A product page that lists "Compatible with Nissan Juke 2010–2019" ranks below one that lists specific engine variants with explicit year ranges and includes cross-reference part numbers from known brands.

TecDoc's granular vehicle catalog structure — the distinction between engine variants, production years, and fitting positions — is precisely the specificity that AI search engines need to confidently cite a page as authoritative. Converting TecDoc's granular data into readable, explicit product page content is what closes the gap between having parts data and capturing AI search traffic.