When entering Tax Account ID numbers to identify States for tax items like State withholding, Aatrix requires a certain format for each state.
Confirm that the State Tax Account ID number that identifies your state is correct via the state's tax website. E.g. The Massachusetts state website is https://mtc.dor.state.ma.us/mtc
If you have obtained the correct number with the state and need to add it within Aatrix, you can do so by going through the Aatrix verificaiton grid and selecting Edit > Company Setup from the menu bar.