Introduction

This post explains GST number validation using Javascript or jQuery on a text change event. You need to apply the "gst" class to control and add the below Javascript function.

GST no sample : 05ABDCE1234F1Z2

Code

  1. <script type="text/javascript">
  2. $(document).ready(function () {
  3. $(".gst").change(function () {
  4. var inputvalues = $(this).val();
  5. var gstinformat = new RegExp('^[0-9]{2}[A-Z]{5}[0-9]{4}[A-Z]1}[1-9A-Z]{1}Z[0-9A-Z]{1}$');
  6. if (gstinformat.test(inputvalues)) {
  7. return true;
  8. } else {
  9. alert('Please Enter Valid GSTIN Number');
  10. $(".gst").val('');
  11. $(".gst").focus();
  12. }
  13. });
  14. });
  15. </script>
  17. ASP Textbox
  18. <asp:TextBox ID="txtGST" MaxLength="15" runat="server" class="gst form-control mandatory" ClientIDMode="Static" placeholder="GST Reg No."></asp:TextBox>
  20. Html input type text
  21. <input type="text" class="gst" >