If you want fully working code, then you may need to use CSS and Javascript along with html. I have written a sample code which contains 10 digits of input and a button. It does the below three functionalities. 1.Each digit allows only numbers and length of a digit is 1. It means you can not enter more than one digit. 2.Once you enter a digit the cursor automatically moves to next digit. 3.On clicking on the button (Get Phone Number) you get the entered phone number as alert. You can change the code as per your need. Code: