Currently the module access (controlled via general ledger > ledger calendars) only stops users from creating journals within that module. For instance but putting the supplier module access to means that no purchase ledger journals can be posted from the purchase ledger module. However these controls can easily be sidestepped. This is because you can still post journals in other modules which affect the sub module you hoped to close. For instance in our scenario above you can still post a general ledger journal and pick an offset account of supplier. Therefore you are able to post to a module that you wanted to be closed. Therefore the idea is that the module access controls should stop all postings to a sub ledger, not just from journals created in that module.