Salesforce B2C Commerce 24.7 > Merchandising Your Site > Campaigns and Promotions > Controlling Promotions > Qualifiers > Using Coupons as Qualifiers > Configure a Coupon

Managing System-Generated Codes

Coupons with over ten thousand codes perform better with system-generated codes. Once the total number of coupons across all sites exceeds one million, replication time slows significantly. System-generated coupon codes don't increase replication time with increased coupon codes.

You can specify system-generated coupon code preferences in Business Manager. Preference changes take effect for new system-generated coupon codes only.

Existing coupons remain configured in the same way as they were generated. Existing coupons continue to generate the same codes as before; so if you export codes you previously exported, you get the same codes.

Release 16.6 provided an algorithm with enhanced randomness and more code length options, making it harder for customers to guess a code. With Release 16.7, all codes, both new and existing use this algorithm.

These preferences are included in site import/export and Staging, like other site preferences.

The prefix of a coupon code is limited to the following characters:

0123456789 abcdefghifjklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ $%/()[]{}=?!._*+~#&@ and space

See Configuring Coupons.

Select site > Merchant Tools > Site Preferences > Coupons.
On the Coupon Preferences page, you can set coupon preferences.
Include or exclude vowels and Y.
For improved security, Salesforce recommends using coupon codes without vowels and Y.
Include or exclude separating dashes.
Specify a code length, from 10 to 20 characters:

A shorter code length results in fewer codes that can be generated. This is most relevant for code lengths shorter than 12 characters.

The format example shows how the code looks.
Click Apply to accept the changes.

These options might result in a situation where the same codes exists for multiple coupons. This can occur for two system-generated coupon codes if their coupon code formats differ only by whether or not vowels were included in the generated codes.

For example, if the preexisting configuration of 16 character codes with dashes and vowels is changed to 16 character codes with dashes but no vowels, then there it's possible that the same code could be generated for two coupons of different formats. If this happens when a coupon code is redeemed, and both coupons are enabled, the newer coupon is considered the owner of the code.