diff --git a/bcutils.js b/bcutils.js
index 187caa1..be7f363 100644
--- a/bcutils.js
+++ b/bcutils.js
@@ -116,8 +116,9 @@ function extractParamsFromTransId(transId) {
 function extractSubParams(param) {
   const subParams = [0, 0];
   if (param.toString().length < 20) {
-    throw 'extractSubparams error to shot:' + param;
-  } else if (param.toString().length > 40) {
+    param = utils.pad(param, 20);
+  }
+  if (param.toString().length > 20) {
     throw 'extractSubparams error to long:' + param;
   } else {
     subParams[0] = param.toString().substr(0, 10);