November 2018
Yes you can register your game on the sims 3 store and still keep it in steam without needing an origin account. I own the game through steam and am registered on the sims 3 website without having anything to do with origin. I have not purchased points though so I am unsure if you need an origin account for that. Have been told there are point cards to purchase to add points but have not found them in any store.
November 2018
@Panda14616 Yes, you need an Origin account to purchase points now, as the Sims 3 store no longer has the ability to handle cash transactions. But it's easy enough to link your store account to Origin, in which case your registered content would be added to your Origin account. (In fact, Origin may already recognize your account credentials without your having to re-register, but I'm not sure.)
You can buy EA cash cards and add them to your Origin account without needing to provide any credit card information, and then you can use the money to buy points, or worlds that require cash instead of points. I've seen the cards on sale at Best Buy; google says they're also offered by Walmart and Target, among other places.
November 2018
I did that and it didn't work
April 2020
April 2020
@kayla20618 What exactly are you trying to do?
May 2021
How did you register it to sims3.com?
May 2021
@talksic3 If you already have an account on the site (www.thesims3.com ), sign in, scroll down to the bottom of the page, click "Register a game," and add the product key. If you don't have an account, you'll be asked to input a key when you're creating one.
Since this thread is a few years old now, I'll lock it here. If you still need help, please create a new thread describing the issue, as well as where you bought the code.