diff --git a/contributing/testing-best-practices.md b/contributing/testing-best-practices.md
index ec6bbba587..a4226f4fe2 100644
--- a/contributing/testing-best-practices.md
+++ b/contributing/testing-best-practices.md
@@ -9,7 +9,9 @@
 
 ## File structure
 
-- Unit and Acceptances tests are in the same `_test.go` file. They are not in the same package as the code tests, e.g. `advancedcluster` tests are in `advancedcluster_test` package so coupling is minimized.
+- Acceptances tests are in corresponding `_test.go` file as the resource or data source source file.
+- General unit tests are in corresponding  `_test.go` file as the resource or data source source file.  If business logic is extracted into a separate file, unit testing for that logic will be including in its associated `_test.go` file (e.g. [state_transition_search_deployment_test.go](https://github.com/mongodb/terraform-provider-mongodbatlas/blob/master/internal/service/searchdeployment/state_transition_search_deployment_test.go)).
+- Tests are not in the same package as the code it tests, e.g. `advancedcluster` tests are in `advancedcluster_test` package so coupling is minimized.
 - Migration tests are in `_migration_test.go` files.
 - All resources need a `main_test.go` file to handle resource reuse lifecycle, e.g. [here](https://github.com/mongodb/terraform-provider-mongodbatlas/blob/master/internal/service/advancedcluster/main_test.go).
 - Helper methods must have their own tests, e.g. `common_advanced_cluster_test.go` has tests for `common_advanced_cluster.go`.