--- a/mod_voipms_carddav/mod_voipms_carddav.lua	Thu Oct 09 14:17:11 2025 +0100
+++ b/mod_voipms_carddav/mod_voipms_carddav.lua	Sat Oct 11 09:52:31 2025 -0400
@@ -50,6 +50,23 @@
         return s
     end
 
+    local function normalize_us_phone_number(number)
+        if not number then return "" end
+
+        local digits = number:gsub("%D", "")
+
+        if #digits == 11 and digits:sub(1, 1) == "1" then
+            digits = digits:sub(2)
+        end
+
+        if #digits ~= 10 then
+            return ""
+        end
+
+        return "+1" .. digits
+    end
+
+
     for vcard_block in response_body:gmatch("BEGIN:VCARD(.-)END:VCARD") do
         local fn = vcard_block:match("FN:(.-)\r?\n") or "Unknown"
         fn = clean_string(fn)
@@ -57,6 +74,7 @@
         for tel_type, tel_number in vcard_block:gmatch("TEL;TYPE=([^:]+):([^\r\n]+)") do
             tel_type = clean_string(tel_type):lower()
             tel_number = clean_string(tel_number)
+            tel_number = normalize_us_phone_number(tel_number)
 
             table.insert(contacts, {
                 name = fn,