Getting Started
If you do not have a tenant for Microsoft Dynamics 365 Business Central, you can sign up for a free trial.
Once you have completed the sign up and your tenant is up and running, you can add the NAV-X National Accounts app from the AppSource marketplace. If you have questions about the installation process of an app through Microsoft AppSource, you can find more information on installing apps on the Microsoft Docs site.
Permission Setup
Permissions for the app must be setup before the National Accounts setup is started to ensure that the users can access the setup and also use the functionality properly once the setup is completed. You can find more information under Permission Setups.
Assisted Setup
To start the Setup
When you are on the role center and have not completed the setup for the NAV-X National Accounts app, you will see a notification asking "Do you want to get started with NAV-X National Accounts?". Select Click here to run the setup to start the Assisted Setup wizard. Alternatively, you can also choose the 
icon, enter Assisted Setup, and then choose the related link.
When you start the Assisted Setup wizard for the first time, the NAV-X End User License Agreement is displayed. Please read the license terms carefully and, if you agree to the terms, please accept them by clicking on Accept. If you do not agree to the license terms, please choose Decline and then uninstall the app from your tenant.
To set up customer posting groups
The next step allows you to configure a new General Ledger account on the customer posting groups. This General Ledger Account is required due to the complex posting of applications between different customers and is called the Cash Receipt (Interim) Account. As it is an interim account, this is used during the posting only and the balance should always be zero.
To set rules
The next step of the Assisted Setup allows you to define whether you want to allow Cross Payment Posting or not. Cross payment posting defines the ability to allow the application of payments or credit memos on one child customer to another (a child customer is a customer assigned to the National Account customer) as long as they are assigned to the same National Account.