diff --git a/dev-docs/bidders/sonobi.md b/dev-docs/bidders/sonobi.md
index 773a17350c..160d3be5c6 100644
--- a/dev-docs/bidders/sonobi.md
+++ b/dev-docs/bidders/sonobi.md
@@ -23,9 +23,12 @@ implementing our adapter please don't hesitate to contact us at apex.prebid@sono
 | `ad_unit`      | required | The adunit ID                                | String        | `'/1234567/example/adUnit/code'` |
 | `floor`        | optional | Bid floor for this placement in USD          | Integer       | `0.50`                           |
 | `sizes`        | optional | Adunit sizes that will override global sizes | Array[String] | `[[300, 250], [300, 600]]`       |
+| `hfa`          | optional | Publisher Unique Identifier                  | String        | `'123985'`                       |
 
 ### Configuration
 
 The `ad_unit` and `placement_id` are **mutually exclusive** but at least one is required. If you pass both, `ad_unit` takes precedence. 
 
 If you pass the optional `sizes` Array in your bid params it will override the global config sizes for the Sonobi Adapter only.
+
+The `hfa` parameter requires your Sonobi Account Manager to enable this feature for you. Please contact them for further information.