Invitbox calls them “GL Codes”.
ARL knows them as the “Accounts”
Again, because of the connectivity between invitbox and ARL if you create or edit your Accounts in ARL you simply need to go to Admin > GL Codes in invitbox, click edit, then click Import from ARL.
If you wish to reduce the number of GL Codes that invitbox presents to you on its drop down lists, go to Admin > GL Codes > edit and un-check the "In Use" box for those that you do not want displayed. Note - by un-checking a GL Code you are not deleting it from invitbox, you are simply excluding it from the list of GL Codes that are available to use within invitbox.
Some things to note:
You cannot post bills to Header Accounts - ARL does not allow it so do not assign Header Accounts as a GL Code to a bill within invitbox.