When entering sales orders, you can select the desired customer for the sales order according to the telephone numbers entered for the customer and customer contacts.
The following set up must be completed:
Enter and maintain the contact information for customers. This information can also be maintained in program CMCM, Customer Credit Maintenance, and program CMMM, Customer Master Maintenance.
When
you enter these programs, instead of entering the customer in the Cust
No field, enter your initials and press the [Telephone] 
button
next to the [Address] or [Addresses] button. The
telephone screen will pop up to allow you to enter the desired telephone
number. You
can exit this screen without entering a telephone by clicking on the main
sales order screen.
You can use also the list of values to select the desired telephone number. When the desired telephone number has been entered, press the tab key or the enter key on your keyboard. The program will search through the customer records and retrieve the customer to which the telephone number belongs.
You can enter a partial phone number with the % wildcard and press F9 to display a list of values of phone numbers based on the partial number entered.