I created a new store with their own store admin user account.
When they attempt to add a sales tax for their store, it shows tax rates that were setup for all other stores and does not allow them to create there own tax rules.
Anyone know what I'm doing wrong here?
You can not set separate rates for the store.
The only thing you can do is set the rates and then set the products appropriate in each store if the products are not shared.
Or you can use EZ Taxjar which will handle all the rates in real-time.
If you don't have a TaxJar account, you can get a 30day free trial here.
So our stores in other states that have different tax rates have to be set by the super administrator?
If you use EZ Taxjar then it will all be done automatically. You don't have to set anything up other than your API key (and optionally your merchants or other store API keys).
You can read the documentation here: https://ez-ms.com/docs/eztj.pdf
And you can get a free trial from Taxjar here.
Otherwise, yes. The admin of the site needs to setup and manage the tax rates for everywhere there is tax liability. The vendor/company would select which taxes might be appropriate for their product. In EU (and many other coutnries) they have a simple VAT tax that covers country, state and local taxes (varies by country). In US and Canada, there are differing rates based on Vendor/Company location and customer shipping address. Alternatively you can use either the Vendor/Company's NEXUS or the site admin NEXUS rather than the origin address.
TaxJar will also do your tax reporting and payment for you as well. Hence you could encourage your vendors/companies to setup their own TaxJar accounts.
Note also that there is NO support in cs-cart for tax thresholds. I.e. if your vendor is in NYC and your customer is in NYC, and they are purchasing garments, the first $100 of the purchase is tax free (NYC tax). TaxJar will handle that, but cs-cart taxation won't. It would be illegal to collect taxes from a customer that ultimately wouldn't be paid to the taxing authority (NYC in this case). But state tax would still apply.
As tax codes are changing in US, it will become increasingly more difficult to manage taxes (and their variations) individually.