diff --git a/src/ebird/api/validation.py b/src/ebird/api/validation.py
index 3250d1a..a048df7 100644
--- a/src/ebird/api/validation.py
+++ b/src/ebird/api/validation.py
@@ -27,18 +27,18 @@ def is_country(value):
 
 
 def is_subnational1(value):
-    return re.match(r"^[A-Z]{2}-[A-Z0-9]{2,3}$", value)
+    return re.match(r"^[A-Z]{2}-[A-Z0-9]{1,3}$", value)
 
 
 def is_subnational2(value):
-    return re.match(r"^[A-Z]{2}-[A-Z0-9]{2,3}-[A-Z0-9]{2,3}$", value)
+    return re.match(r"^[A-Z]{2}-[A-Z0-9]{1,3}-[A-Z0-9]{2,3}$", value)
 
 
 def is_region(value):
     return (
         re.match(r"^[A-Z]{2}$", value)
-        or re.match(r"^[A-Z]{2}-[A-Z0-9]{2,3}$", value)
-        or re.match(r"^[A-Z]{2}-[A-Z0-9]{2,3}-[A-Z0-9]{2,3}$", value)
+        or re.match(r"^[A-Z]{2}-[A-Z0-9]{1,3}$", value)
+        or re.match(r"^[A-Z]{2}-[A-Z0-9]{1,3}-[A-Z0-9]{2,3}$", value)
     )