What the NAV connection options do

On the Team Settings page, Integrations tab, NAV credentials card, four checkboxes switch the NAV features on one by one. Each needs the team's own NAV technical user; anything left unticked does not run.

First enter the NAV technical user on the card (Login, Password, Signing Key, Tax Id). You create the technical user on NAV's Online Invoice site; give it the Invoice Management and Invoice Query permissions. Save stores the settings.

Validate Hungarian tax numbers via NAV Checks a Hungarian partner's (customer's or supplier's) tax number in NAV's register when you look up the tax number on the partner, and during the weekly automatic partner check. Not needed for the other features.

Auto-fill company data from NAV When a valid Hungarian tax number is looked up, fills in the partner's name, address and sites. Only works when tax number validation is on too.

Synchronize invoices from NAV Every hour, downloads the incoming and outgoing invoices reported to NAV, with their line items, and adds them to the Demona invoice list.

Reconcile existing invoices with NAV data Compares invoices already in Demona with NAV's data. Re-fetching an invoice's line items or its invoice chain (for example modifying invoices) also depends on it.

The four features can be switched independently, except that auto-fill builds on tax number validation. Looking up your own company details (at sign-up and on the billing address) does not depend on any of them.