Lookup Lists: Transaction Data Enrichment

Last updated: April 8, 2026

Lookup Lists allow you to enrich incoming transaction data with external reference information in real-time. Users can manage dynamic data—such as blacklists, risk ratings or merchant classifications—with minimal effort.

A Lookup List is a key-value (or input-output) dataset used to enhance transaction records. When a transaction is processed, the system matches a specific transaction field against the Input in your list and retrieves the corresponding Output. This retrieved data is stored in a dedicated Enrichment section of the transaction data model.

Core Benefits

  • Operational Agility: Compliance Managers can directly manage and update reference data, reducing the time-to-market for rule adjustments.

  • Enhanced Investigations: Analysts receive immediate context during triage via enriched data fields displayed on the transaction details screen.

     

Using Lookup Lists

To utilize lookup lists for transaction enrichment, follow these steps:

1. Create a new List 

  • Create a List: In Settings > Risk Policy > Lookup lists, create a new list, naming the list itself, the Input name and Output name. Choose the Input and Output data types.

  • Schema Naming: Note down the Input and Output names, which need to match the headers of the CSV file in step 3.

2. Add Lookup List Mappings

Next, specify which transaction data (or block) will be mapped using the Lookup list.

  • Source Field: Identify the incoming transaction field or a block (a predefined abstracted data field, such as "Counterparty ID") that provides the Input for the lookup.

  • Output Field: Define a unique name for the enrichment field where the retrieved Output will be stored.

3. Data Preparation and Upload

The system manages data through CSV imports for efficiency. 

  • File Format: Prepare a CSV file containing these columns: Input, Output, and optionally a third column Notes. The first row will contain the Input name and Output name, which must match the ones you provided when creating the list. 

  • Provide Data: Fill the CSV file with the Input-Output pairs, and optionally adding notes in the third column. The inputs must be unique.

  • Upload: Upload the file. The system supports files up to 10,000 rows. 

4. Draft Management and Publishing

To maintain data integrity, lookup lists are versioned.

  • Draft Mode: New uploads or edits are saved as a draft. Transactions do not utilize draft versions for active lookups.

  • Publishing: Once verified, choose "Promote draft" to make it active.

  • Versioning: The system maintains a historical record of all published versions, including timestamps and the user responsible for the update.

  • Constraints: Up to 20 lookup lists can be active at the same time.

5. View and Use Enriched Data in Scenarios

Once a Lookup List is published, incoming transactions will be enriched using the lookup list where a match can be found, using the Mapping specified in step 2. 

The Enriched information will be used in scenarios, and is visible in the Transaction detail in Mesh.

  • Processing Logic: The system performs case-insensitive comparisons and trims leading/trailing whitespace from source fields while matching the transaction data with the Input section of a published lookup list.

  • Match: If a match is found, the incoming transaction is enriched with the equivalent Output from the lookup list.

  • Use in Scenarios: The enriched data field can be used in your scenarios just like any transaction or customer field. 

    • For example, if the Output field was called "Retail Type" in the lookup list and it was a string type

    • To reference this in a scenario, use transaction.enrichments.retail_type.

    • i.e. the name of the data field itself will be lowercase and using underscores instead of spaces

  • Transaction Details: A dedicated section labeled "Enrichment" displays the enriched data.

6. Updating the List

To update an existing list, create a draft version of the list by choosing Actions > Upload new file. This will create a new draft version of the list.

Once the new list has been successfully uploaded, you can promote this draft to make it active. This will deactivate the previous version of the list.