How made the id of customer auto increase numeric

how to made the customer id look like this
start with specific id like 1005 then increase automatically
Customer 1: 1005
Customer 2: 1006
Customer 3: 1007

for that you can use multi approach.

like you follow this

  1. add custom data field in customer doctype
  2. on validate method of customer use autoname method in python side and save return value of autoname in custom field, but here you have to add condition if field is blank then it works otherwise pass the code
  3. set custom field in naming rule


okey but in logic
i add this for all doctypes??!

yes, you can make common method and add fields in many doctype but field name will be same

You can use Document Naming Rule

You can setup prefix for document number and set Digits for it