You can have multiple users logged in to the one account at the same time from different locations (or even from the same location). However they would need to use the same username and password as you use for your Tally account.
There is no facility to create multiple login accounts or to set different levels of access.
One option could be to use our API. The API allows other computer programs (such as your website) to exchange data with your Tally account You may need to use the services of a 3rd party developer as the API isn’t exactly as easy to use as Tally is!
We are currently working on introducing full multi-user access shortly.