How to Find User Exits for Billing using SPRO

ABAP programmers and SAP professionals can use SPRO transaction to find user exits for billing, user exits for sales, or for shipping, etc.

Launch SPRO and switch to Display IMG (Customization Implementation Guide) view.
Drill down SPRO customization menu by following path:
Sales and Distribution > System Modifications > User Exits

As seen in below screenshot, under System Modifications: User Exits, there are number of options to see available user exits for your ABAP developer to use.

User Exits:
User Exits For Price Determination
User Exits For Partner Determination
User Exits For Credit Checks and Risk Management
User Exits in Sales
User Exits For Shipping
User Exits For Transportation
User Exits For Billing
User Exits For General Billing Interface
User Exits For Sales Support
User Exits For Lists
User Exits For Payment Cards

For billing user exits, if you click on the IMG activity documentation a list of user exits for billing is listed with detailed information about why and how to use this user exit in your custom ABAP development tasks.

Just to take a list of available user exits in Billing, I copied down the names here:
USEREXIT_NUMBER_RANGE,
USEREXIT_ACCOUNT_PREP_KOMKCV,
USEREXIT_ACCOUNT_PREP_KOMPCV,
USEREXIT_NUMBER_RANGE_INV_DATE,
USEREXIT_FILL_VBRK_VBRP,
USEREXIT_PRINT_ITEM,
USEREXIT_PRINT_HEAD,
USEREXIT_RELI_XVBPAK_AVBPAK,
USEREXIT_NEWROLE_XVBPAK_AVBPAK,
USEREXIT_NEWROLE_XVBPAP_AVBPAK, and
EXIT_SAPLV60B_001 to EXIT_SAPLV60B_011