Sims 3 code already redeemed
Code redemption
If you're not sure how to redeem a code, please read this article:
https://help.ea.com/in/help/origin/origin/origin-code-redemption-faq/
Before trying any other troubleshooting, please confirm that you're entering the correct code. The letter o and number zero can look the same, as can the letter i and the number one, etc.
Please keep in mind that product codes cannot be removed from one account to free them up for another.
If you previously registered your product code(s) on the old Sims 3 site (www.thesims3.com or store.thesims3.com), the code will read as used because Origin and that site share information. The associated content will be in the game library of an Origin account tied to the email address you used on the site, even if you never used Origin yourself at the time.
If you remember what email address is associated with your old account, you can login to Origin with it and download your content from your game library. You can also merge your old account into your new one, but please be aware that while the Sims 3 base game and packs usually transfer over without issues, any store content owned by the old account will not be preserved.
If you can't remember what email address you used on the old site, try entering the addresses you remember in an Origin login window and clicking "Forgot your password?" Any address associated with an Origin account should receive a password recovery email. Be sure to check the spam folder as well as the inbox.
If you are unable to recover your old account in this way, you can try contacting EA customer support. However, there is no guarantee that a support rep may be able to help you, depending on how much information you can remember about the old account.
What may help is for you to provide proof of ownership: a photo that includes a disc, its case, and the insert from inside the case with the product code showing and legible. You can upload photos when submitting the help request. This alone will likely not be sufficient to recover your old account, but it may allow the support rep to work with you to provide the additional information necessary.
https://help.ea.com/en/contact-us/
When you buy the Sims 3 base game or a pack through Origin, the content is automatically added to your account, with no further action necessary. The base game code cannot be reused on a different account; you'll need to sign into the account that made the purchase in order to access it.
If you bought your content from a third party, you'll need to contact that vendor. Approved sellers of EA games are responsible for providing working product codes. Here's a list:
https://help.ea.com/en/help/faq/where-to-buy-ea-games-v2/
If you bought from an unauthorized third-party seller, you may have received a bad code, in which case there is no way to use it. Nor is EA responsible for replacing an invalid code with a working one. Hopefully you'll be able to receive a refund from the seller.
When you buy a store world, you need to register it on the Sims 3 Store site, not within Origin. Go here:
Sign in with the same credentials you use in Origin, scroll to the bottom of the page, click Redeem a Code, and enter the 16-character code. Like the base game and packs, codes for store worlds can only be used once, after which they're permanently tied to that account.
If your product code cannot be redeemed and you bought it from Origin, please contact EA customer support for help.
If your product code cannot be redeemed and you bought it from a third party, please see the above sections for discs and digital copies.