Incorrect Voucher Code
Usually, the “Incorrect Code” message shows when students mistakenly paste the code in the coupon box. You must paste this code into the “Voucher/Promotion Code” box.
You can do so when you log in to your GED.com account and click on the “Study” button. Then, please choose “Practice” and click “Buy Subject.” You will be redirected to the product page.
When you click “Buy Subject,” you will be redirected to the product page and you can see the “Have a voucher code? Redeem now” link. Click on this link and follow the instructions on the page.
Please remember that if you miss this field and paste the code into the “Coupon” box, you will get an “incorrect code” message.
For more details, please check this page: https://onsego.com/help/how-to-redeem-your-ged-ready-vouchers/.