Auto Parts Cross Reference Explained

March 24, 2023

Cross-reference part numbers, sometimes referred to as interchangeable part numbers, or equivalent part numbers is a widely adopted technique used within the parts data industry to link two parts that should be (mostly) the same. The method is often used for substitute-selling parts manufactured by other brands to buyers, or for inferring information. 

While this practice is widely popular, and overall provides a lot of benefit to different businesses throughout the auto parts supply-chain, it does not come without its downsides and issues that need to be considered. We’ll explore some of the cost-benefit considerations and take a look at how this technique should be used as well as other areas where it should potentially be avoided. 

The benefits of cross-referencing


One obvious benefit of knowing additional equivalent fitting parts is the opportunity to substitute-sell. A customer searching for a particular branded part may be offered an equivalent part from a separate brand. This process is even more powerful in the online world where substitute-selling can be automated and integrated into tools such as vehicle searches and part filtering systems. 

Even outside of the online world, substitute-selling is far easier when cross-referenced parts are properly documented. 

Search engine optimisation

For businesses in the world of ecommerce, search engine optimization (or “SEO”) is one of the most powerful tools for marketers and sales managers. This is no different in the parts industry. In fact, cross-referencing presents a unique opportunity for auto parts ecommerce which is not an option for most other ecommerce categories. 

The vast majority of part buyers start their purchasing journey via a search engine such as Google. For buyers searching for replacement parts, much of the time they have located the part number physically printed on the part itself. Then, when searching to buy the part their search term often includes an OEM part number. For an aftermarket parts seller, referencing the OEM or original part number with the equivalent aftermarket product being sold is essential to rank highly for the buyers’ search results. 

The problems with cross-referencing

Accuracy management

When managing millions of cross-referenced part numbers that all link with one another in a large network, maintaining a high level of accuracy is the largest challenge. Bad input data is the bane of every data manager. 

It is often in the best interest of suppliers and manufacturers to not publicly share cross-reference information, and therefore much of this data is not widely available. Often it is the fitters of the parts who have built-up specialized knowledge about the interchangeability of certain part types and brands. However, once again, in this case, the knowledge is gated rather than shared. This industry situation can lead to fragmentation of data and therefore cause incomplete information outputs. 

Data standardization

Like any sector of auto parts data, standardization of structures and naming conventions is always a challenge. Cross-referencing is not immune to this problem. Businesses throughout the parts supply chain from manufacturers and data aggregators, to distributors and retailers, often use different structures and names for parts and their details. This means that it becomes very difficult to cross-reference two parts that, in practice, may be the same (interchangeable) but may be referred to with completely different names. This problem multiplies when different languages are taken into consideration.

In order to account for this issue, cross-referring needs to be backed by a standard. This means that the structure and naming of vehicles as well as the categorisation or parts is defined for all brands. This acts as a centralized and common information protocol to link parts with the correct data, ensuring that internally you are speaking the same language. In addition, it becomes easy to share this standardized data with third-party partners.

Partly’s solution to cross-referencing

Partly has a unique approach to cross-referencing which mitigates the problems commonly encountered in the industry, while providing huge benefits. The cross-referencing system leverages both the Universal Vehicle Database as well as the Partly Catalog. 

The data standards provide the common structure and naming conversions. This means there is a defined baseline and set of IDs that can be referenced by any business throughout the auto parts supply chain and be commonly understood.

The Partly Catalog aggregates all cross-referenced parts into one part ID, which is then analyzed for inconsistencies between each linked part. This technique highlights potential data inaccuracies and makes predictions where data (such as fitments or part attributes) may be incomplete. 

The above techniques go a long way towards solving the standardization and accuracy problems. The additional benefits for ecommerce are found in the Partly digital infrastructure. Partly’s APIs allow businesses to query parts data with flexibility and access aggregated cross-reference data from thousands of sources, processed through the Partly Catalog integrity checking system. This makes it easy to ingest your own data and use it scalably online and throughout your ecommerce channels.