Unable to Change Promotion Coupon Code from Multiple Uses to Single Use

Consider the following scenario:

1. Create a Standard or Advanced Promotion. For more information, see Promotions.
2. In the New Promotion form > Codes tab> select either Multiple Use or Single Use for Number of Uses.
3. Fill out other mandatory fields and click Save.
4. Edit the promotion and click the Codes tab.

Result: The Number of Uses can no longer be changed.

By design, the user can no longer edit the Number of Uses field on a promotion once it is saved. This remains the case whether the promotion had been used or not.