How make customer id number in quick-books

I got your back, @mukesh3.

To clarify, are you referring to adding the ID number of your customers to their profiles? If yes, the option to do so is unavailable. No worries, I've provided a few workarounds you can use. 

You can utilize the Notes or Other field to add their ID numbers. However, this will not show on the sales form you'll make for them, you can only see it on the customer page. Here's how to do it:

1. Go to the Sales menu and click Customers.
2. Look and select the customer's name you need to make an ID number.
3. Next, select the Edit button.
4. Add the ID number in the Other box or from the Notes field.
5. Once done, click Save. 

If you want the ID number to be displayed on their sales forms, you can add a custom field to your template. Once done, manually enter the information when you create a transaction for them. Let me guide you how:

1. Select the Gear icon and choose Custom form styles. 
2. Find the template you use and click the Edit option. You can also create a new one by clicking the New style dropdown.
3. Once opened, select the Content tab and click the Header part.
4. Scroll down to the Display section and select +Custom field.
5. From the box, enter the word Customer ID number.
6. When everything is fine, select Done. 

For reference, check out this article: How to add custom fields to sales forms and purchase orders. It also includes steps on how you can inactivate or edit a custom field.

Another option is to add the ID number in the Company field from the customer page if you don't want to manually add them for every transaction. This information will both show on their sales form and their profiles. Refer to the steps below:

1. Go back to the Sales menu and select Customers.
2. Locate and click the customer's name you need to add an ID number.
3. Next, select Edit.
4. From the Company box add the ID number before the name. Example: Customer ID number: 000 - Company name.
5. Once done, click Save. 

Getting a list of your customers’ outstanding balances will help you determine how much still due and how long they’re past due are. You just simply need to run the accounts receivable ageing report to have this data. 

I'm always around here in the Community if you need further assistance about making customer ID numbers. Just simply click the Reply button to add your response. I'll be waiting for your results. Take care.