diff --git a/geomagio/Controller.py b/geomagio/Controller.py
index 8dcb3eaea1d13f13783e73729c328fd47682df2d..f84006bb8f169336639ffaf35375c25648d6af6b 100644
--- a/geomagio/Controller.py
+++ b/geomagio/Controller.py
@@ -566,9 +566,11 @@ def parse_args(args):
             metavar=('FROM', 'TO'),
             nargs=2)
     parser.add_argument('--locationcode',
-            choices=['R0', 'R1', 'RM', 'Q0', 'D0', 'C0'])
+            help='EDGE location code, e.g. "R0", "R1"',
+            type=edge.LocationCode)
     parser.add_argument('--outlocationcode',
-            choices=['R0', 'R1', 'RM', 'Q0', 'D0', 'C0'])
+            help='EDGE output location code (when different from --locationcode)',
+            type=edge.LocationCode)
     parser.add_argument('--interval',
             default='minute',
             choices=['hourly', 'minute', 'second'])
diff --git a/geomagio/edge/LocationCode.py b/geomagio/edge/LocationCode.py
new file mode 100644
index 0000000000000000000000000000000000000000..c4eefa949ed0b87755adac6388786552f2d59f55
--- /dev/null
+++ b/geomagio/edge/LocationCode.py
@@ -0,0 +1,31 @@
+"""EDGE Location Code argument validation."""
+
+import argparse
+import re
+
+
+def LocationCode(code):
+    """EDGE Location Code argument validator.
+
+    Location Code is the last component in a channel identifier;
+    SNCL => Station, Network, Channel, Location Code
+
+    Parameters
+    ----------
+    code : str
+        the code to validate
+
+    Returns
+    -------
+    str
+        validated lcoation code.
+
+    Raises
+    ------
+    argparse.ArgumentTypeError
+        if the location code doesn't match the regular expression.
+    """
+    try:
+        return re.match('^[A-Z0-9]{2}$', code).group(0)
+    except:
+        raise argparse.ArgumentTypeError('Invalid location code, expected /^[A-Z0-9]{2}$/')
diff --git a/geomagio/edge/__init__.py b/geomagio/edge/__init__.py
index 1555f9579b474bd36e402082663ba1923dc3188c..ba615d36c791013dd5e9be3d29709bdb5dbecb90 100644
--- a/geomagio/edge/__init__.py
+++ b/geomagio/edge/__init__.py
@@ -2,9 +2,11 @@
 """
 
 from EdgeFactory import EdgeFactory
+from LocationCode import LocationCode
 from RawInputClient import RawInputClient
 
 __all__ = [
     'EdgeFactory',
+    'LocationCode',
     'RawInputClient'
 ]