SAMS is a record/number that nonprofit organizations need before they can apply for a government grant. It is necessary to update it at least once a year in order to keep your SAMS number in an active state.
It is recommended that GrantHub users print their SAMS record to pdf and upload it to the Answer Library. Here they will be able to set an expiration date. You should also consider setting yourself a task as a reminder to update it before it expires. You can set a general task that isn't connected to a funder or opportunity on the Tasks tab found on the My Profile page. (My Profile can be accessed by selecting the blue 'Welcome, Your Name' menu in the upper right corner of your screen.)