For generating batches of bulk coupon codes we recommend you to install an app from the BigCommerce Apps Marketplace named, Coupon Manager.
After installing this app it has a 4-step process to generate coupon codes.
1. Click on 'Generate Coupon Codes'.
2. Setting up of the batch includes giving the batch a name for your own sake. Then select the type of coupon and the amount/percentage of discount. Then in optional settings, you can set a common prefix of the batch of codes which you wish to have. Rest all the fields are actually optional to fill and self-explanatory.
3. In the next step, you have to enter the number of codes that you want to generate for the batch.
4. Once you're done, you will have to go to the 'Import' tab of the app and download the CSV file which contains the batch of codes.
After downloading the CSV file, copy the codes and paste them into the console in the Manage Codes section of the redemption option for which the codes were generated. Make sure to enter one code per line which can be achieved if copied and pasted from the CSV file to the console as it is.
Hit save and you are ready with a fresh batch of coupon codes.