diff --git a/esphome/components/sml/__init__.py b/esphome/components/sml/__init__.py
index f3b6dd95ef..789732dfd6 100644
--- a/esphome/components/sml/__init__.py
+++ b/esphome/components/sml/__init__.py
@@ -32,7 +32,7 @@ async def to_code(config):
 
 def obis_code(value):
     value = cv.string(value)
-    match = re.match(r"^\d{1,3}-\d{1,3}:\d{1,3}\.\d{1,3}\.\d{1,3}$", value)
+    match = re.match(r"^(?:\d{1,3}-\d{1,3}:)?\d{1,3}\.\d{1,3}\.\d{1,3}$", value)
     if match is None:
         raise cv.Invalid(f"{value} is not a valid OBIS code")
     return value