> For the complete documentation index, see [llms.txt](https://docs.zingg.ai/zingg/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.zingg.ai/zingg/running-zingg/set-deterministic-matching-conditions.md). # Set Deterministic Matching Conditions {% hint style="info" icon="right-long" %} Deterministic matching is Enterprise only. Available in Enterprise Lite and above. {% endhint %} To configure deterministic matching, define each rule as a `DeterministicMatching` condition in Python or as a `matchCondition` block in JSON, then pass all conditions to `setDeterministicMatchingCondition()`. Full Python and JSON examples → [Configure Zingg](/zingg/running-zingg/configure-zingg.md) ### How the conditions work Each `matchCondition` is evaluated independently. Any pair that satisfies at least one condition is resolved as a match with a score of 1. You can define as many conditions as your data requires. Using the example above:

Condition	What it means
`fname` + `stNo` + `add1` match `exactly`	Same first name at the same street number and address line → treated as same entity, score 1.
`fname` + `dob` + `ssn` match `exactly`	Same first name, date of birth, and SSN → treated as same entity, score 1.
`fname` + `email` match `exactly`	Same first name and email address → treated as same entity, score 1.

When should I use deterministic matching?

Use deterministic matching when your data contains reliable unique identifier fields where an exact match between two records should always mean they are the same entity. Good candidates for deterministic rules: * First name + email address * First name + date of birth + national ID * First name + street number + address line 1 Do not use deterministic matching on fields that are frequently incomplete or inconsistent. Null values or formatting variations will cause valid matches to be missed. Apply deterministic rules only to fields you trust. If you are unsure, start with probabilistic matching only. Add deterministic rules once you have reviewed match output and identified high-confidence identifier combinations in your data. {% hint style="success" icon="right-long" %} **Read more:** [Configure Zingg](/zingg/running-zingg/configure-zingg.md) | [Concepts glossary](/zingg/frequently-asked-questions/concept-glossary.md) {% endhint %}

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