diff --git a/datacontract/export/bigquery_converter.py b/datacontract/export/bigquery_converter.py
index c69912e7..207e8cc4 100644
--- a/datacontract/export/bigquery_converter.py
+++ b/datacontract/export/bigquery_converter.py
@@ -44,7 +44,7 @@ def to_fields_array(fields: Dict[str, Field]) -> List[Dict[str, Field]]:
 
 
 def to_field(field_name: str, field: Field) -> dict:
-    bq_type = map_type_to_bigquery(field.type, field_name)
+    bq_type = map_type_to_bigquery(field)
     bq_field = {
         "name": field_name,
         "type": bq_type,
@@ -79,37 +79,46 @@ def to_field(field_name: str, field: Field) -> dict:
     return bq_field
 
 
-def map_type_to_bigquery(type_str: str, field_name: str) -> str:
+def map_type_to_bigquery(field: Field) -> str:
     logger = logging.getLogger(__name__)
-    if type_str.lower() in ["string", "varchar", "text"]:
+
+    field_type = field.type
+    if not field_type:
+        return None
+
+    if field.config and "bigqueryType" in field.config:
+        return field.config["bigqueryType"]
+
+    if field_type.lower() in ["string", "varchar", "text"]:
         return "STRING"
-    elif type_str == "bytes":
+    elif field_type.lower() == "bytes":
         return "BYTES"
-    elif type_str.lower() in ["int", "integer"]:
+    elif field_type.lower() in ["int", "integer"]:
         return "INTEGER"
-    elif type_str.lower() in ["long", "bigint"]:
+    elif field_type.lower() in ["long", "bigint"]:
         return "INT64"
-    elif type_str == "float":
+    elif field_type.lower() == "float":
         return "FLOAT64"
-    elif type_str == "boolean":
+    elif field_type.lower() == "boolean":
         return "BOOL"
-    elif type_str.lower() in ["timestamp", "timestamp_tz"]:
+    elif field_type.lower() in ["timestamp", "timestamp_tz"]:
         return "TIMESTAMP"
-    elif type_str == "date":
+    elif field_type.lower() == "date":
         return "DATE"
-    elif type_str == "timestamp_ntz":
+    elif field_type.lower() == "timestamp_ntz":
         return "TIME"
-    elif type_str.lower() in ["number", "decimal", "numeric"]:
+    elif field_type.lower() in ["number", "decimal", "numeric"]:
         return "NUMERIC"
-    elif type_str == "double":
+    elif field_type.lower() == "double":
         return "BIGNUMERIC"
-    elif type_str.lower() in ["object", "record", "array"]:
+    elif field_type.lower() in ["object", "record", "array"]:
         return "RECORD"
-    elif type_str == "struct":
+    elif field_type.lower() == "struct":
         return "STRUCT"
-    elif type_str == "null":
+    elif field_type.lower() == "null":
         logger.info(
-            f"Can't properly map {field_name} to bigquery Schema, as 'null' is not supported as a type. Mapping it to STRING."
+            f"Can't properly map {field.title} to bigquery Schema, as 'null' \
+                 is not supported as a type. Mapping it to STRING."
         )
         return "STRING"
     else:
@@ -117,6 +126,6 @@ def map_type_to_bigquery(type_str: str, field_name: str) -> str:
             type="schema",
             result="failed",
             name="Map datacontract type to bigquery data type",
-            reason=f"Unsupported type {type_str} in data contract definition.",
+            reason=f"Unsupported type {field_type} in data contract definition.",
             engine="datacontract",
         )
diff --git a/datacontract/export/sql_type_converter.py b/datacontract/export/sql_type_converter.py
index 9dcd8fe6..87ca522e 100644
--- a/datacontract/export/sql_type_converter.py
+++ b/datacontract/export/sql_type_converter.py
@@ -269,16 +269,7 @@ def convert_type_to_sqlserver(field: Field) -> None | str:
 
 def convert_type_to_bigquery(field: Field) -> None | str:
     """Convert from supported datacontract types to equivalent bigquery types"""
-    field_type = field.type
-    if not field_type:
-        return None
-
-    # If provided sql-server config type, prefer it over default mapping
-    if bigquery_type := get_type_config(field, "bigqueryType"):
-        return bigquery_type
-
-    field_type = field_type.lower()
-    return map_type_to_bigquery(field_type, field.title)
+    return map_type_to_bigquery(field)
 
 
 def get_type_config(field: Field, config_attr: str) -> dict[str, str] | None:
diff --git a/tests/fixtures/bigquery/export/bq_table_schema.json b/tests/fixtures/bigquery/export/bq_table_schema.json
index 4aafc69a..e9d63671 100644
--- a/tests/fixtures/bigquery/export/bq_table_schema.json
+++ b/tests/fixtures/bigquery/export/bq_table_schema.json
@@ -267,7 +267,13 @@
             "scale": null
           }
         ]
+      },
+      {
+        "name": "custom_type_field",
+        "type": "DATETIME",
+        "mode": "NULLABLE",
+        "description": "Change the datacontract type to a BigQuery type."
       }
     ]
   }
-}
\ No newline at end of file
+}
diff --git a/tests/fixtures/bigquery/export/datacontract.yaml b/tests/fixtures/bigquery/export/datacontract.yaml
index a03a6359..db64e931 100644
--- a/tests/fixtures/bigquery/export/datacontract.yaml
+++ b/tests/fixtures/bigquery/export/datacontract.yaml
@@ -180,4 +180,10 @@ models:
             Field2:
               type: double
               required: true
-              description: a double field
\ No newline at end of file
+              description: a double field
+      custom_type_field:
+        type: string
+        required: false
+        description: Change the datacontract type to a BigQuery type. 
+        config:
+          bigqueryType: DATETIME