Use an invitation code

Enter your code in the invitation field offered during signup or on Membership. Copy it carefully, without extra spaces, and submit it once.

Read the result to see the access granted. A code may have a use limit or an end date. A plan choice alone does not redeem a code.

If the code fails, check for typing errors and review the invitation. Then contact support from the invited email address. Do not post the code in public.

Access with no end date still follows the plan's feature limits, including the monthly custom-book allowance.