Updated 8 October 2026 · SimplyX implementation guidance
Keep invoicing in your ERP
SimplyX RTIR processes invoice data received through API or SFTP. If your ERP does not produce NAV XML, we map its source fields to the structure needed for submission.
What we need to review
- ERP name, version and invoicing module.
- API documentation or an anonymised sample file for SFTP delivery.
- When and how new or corrected invoice data is sent.
What needs mapping?
For each field, we record its source and conversion rule. We review invoice identity, supplier and customer details, dates, currency, tax treatment, line amounts and correction references. The NAV interface specification defines the exact field requirements.
A mapping example
| Source field | Use | Action |
|---|---|---|
| invoice_number | Invoice identity | Preserve identity and references |
| currency_code | Currency | Map and check the currency code |
| tax_category | Tax treatment | Confirm business meaning with finance |
If a required business field is missing, finance and IT need to establish its source.
What do we test?
- Ordinary invoices, corrections and cancellations where applicable.
- Currencies, rounding and different tax treatments.
- Missing data, NAV rejection and interrupted connectivity.
- Actual NAV processing results and the ability to retrieve them.
Who does what?
Your ERP team provides invoice data and the agreed data handoff. SimplyX handles the conversion, submission and NAV status tracking covered by the integration. Before launch, we agree who corrects business data and who responds to technical failures.
Questions before implementation
Can mapping invent fields missing from our ERP?
No. Mapping can transform available data but cannot establish missing business facts. Required information and its owner must be identified during scoping.
Is a named ERP automatically a ready-made integration?
No. The version, module, export or API, fields and workflow determine the integration. Production support should be confirmed for the actual configuration.
Sources
The steps above are SimplyX implementation guidance. The official NAV interface documentation defines the technical requirements.
Related guides
Send your ERP name, VAT-registration stage, invoice volume and source format.