diff --git a/lists/phone_numbers/list.json b/lists/phone_numbers/list.json
index 3ed89e4..2b1de57 100644
--- a/lists/phone_numbers/list.json
+++ b/lists/phone_numbers/list.json
@@ -1,6 +1,8 @@
 {
   "description": "Numbers that cannot be attributed because they reserved for different purposes.",
   "list": [
+    "/((?:\\+|00)1?)([0-9]{3})55501([0-9]{2})/g",
+    "/((?:\\+|00)1?)55501([0-9]{2})/g",
     "/((?:\\+|00)33?|0?)(19900|26191|35301|46571|53649|63998)([0-9]{4})/g",
     "/((?:\\+|00)33?|0?)(999)([0-9]{6})/g"
   ],
@@ -10,5 +12,5 @@
   ],
   "name": "Unattributed phone number.",
   "type": "regex",
-  "version": 20201028
+  "version": 20201030
 }
diff --git a/tools/generate_phone_numbers.py b/tools/generate_phone_numbers.py
index 0dfece5..7502b73 100644
--- a/tools/generate_phone_numbers.py
+++ b/tools/generate_phone_numbers.py
@@ -4,6 +4,15 @@
 from generator import get_version, write_to_file
 
 
+def generate_american_warninglist():
+    # Warning list for fictitious telephone numbers in the US
+    warninglist = [
+        '/((?:\+|00)1?)55501([0-9]{2})/g',
+        '/((?:\+|00)1?)([0-9]{3})55501([0-9]{2})/g'
+    ]
+    return warninglist
+
+
 def generate_french_warninglist():
     regex = '/((?:\+|00)33?|0?)(%s)([0-9]{%s})/g'
 
@@ -30,6 +39,7 @@ def process(warninglist_name):
     }
 
     warninglist = generate_french_warninglist()
+    warninglist.extend(generate_american_warninglist())
     # The list can be extended by adding other entries: `warninglist.extend(generate_some_warninglist())`
 
     description['list'] = warninglist