Confused whether to make user input account number in the beginning or end

Question

i want to make form for opening bank account. I'm thinking about asking the user first if they have already an account in that bank, and then ask them their account number. After they filled it, the system will detect in two different ways. If the user is a customer, system will give them a simple form to be fill. But if they don't have, they will got a long form and must filled all of the field.

Now i'm concern about the journey, will user end up abandon the form because i ask them their bank account number first or no? :/

One more question, if the user is customer. Should i make the form with prefilled field (All field will show up, but user cant edit it) or i just give them a simple form(User cant see what is being prefilled, but the form appearances will be likely more simple)

Thanks!

Answer 1

Since you have two different types of form specifically designed for a specific user (Existing / New), it's important that you ask your existing users to enter their account number or card number (users generally hesitate to provide account number, but they are less hesitant to share card number) to validate. That's the only way for a system to know existing users.

As an online user when I tell the system that I'm an existing customer, I'm mentally prepared to give some evidence of it. So, I don't think I will abandon the form just because I have to provide account number or card number.

On your second question:
Displaying a form with pre-filled read-only information or a fresh form? It depends on whether you want to get some information from users or just display existing information.

As I understand from your question, you are asking users to provide information in the given form, so don't pre-fill any information, just give a fresh form to fill. Showing pre-filled information can be vulnerable - because if somebody knows my account number but not password, the pre-filled information can be an easy treat to the thief.

Answer 2

If the user is already a customer, then shouldn't he fill the form after he logs in? That way, someone who just knows the account number cannot fill in a form for me and create a new bank account.

1. I would ask if you are a customer
2. If yes, log in - post log in, you can pre-fill the text fields. 2a. To make the pre-fill data editable or non-editable depends on the type of data. eg: if it is showing his/her address and if that is field which can be updated without any verification then it can be editable and also if that will affect the customers banking procedures like loan etc then don't allow to edit.
3. If not a customer, show the long form