diff --git a/modules/clan/phonebox/default.nix b/modules/clan/phonebox/default.nix
index 1745371..0c64014 100644
--- a/modules/clan/phonebox/default.nix
+++ b/modules/clan/phonebox/default.nix
@@ -70,8 +70,29 @@
               secret = true;
             };
           };
-          script = ''
 
+          prompts = {
+            server-prefix-number = {
+              persist = true;
+              type = "line";
+              description = "Server prefix number: the first number of [X000]";
+            };
+            ata-local-number = {
+              persist = true;
+              type = "line";
+              description = "Local suffix number: 3 last number of [0XXX]";
+            };
+            ata-password = {
+              persist = true;
+              type = "hidden";
+              description = "Password for SIP registration.";
+            };
+          };
+
+          script = ''
+            cat $prompts/server-prefix-number > $out/server-prefix-number
+            cat $prompts/ata-local-number > $out/ata-local-number
+            cat $prompts/ata-password > $out/ata-password
           '';
         };