Link4 Integration Guide - New Zealand (NZ)
🎯 Purpose
This guide explains the mandatory technical and data requirements for organizations integrating with Link4 to send and receive electronic invoices.
Before integration, ensure your ERP, Accounting System, or Middleware can supply all required data.
Missing or incorrect data will result in:
- invoice rejection
- validation errors
1️⃣ Supported Integration Method
API Integration
Your system (ERP, accounting software, or middleware) sends transactions and contact data to Link4 via a secure API.
Requirements
API endpoints provided by Link4
OAuth or API key Authentication
Valid JSON Payload structure
Data validation compliance
2️⃣ Supported Transaction Types
Document Type | Description | ||
Invoice | Standard commercial invoice | ||
Credit Note | Reduces or cancels an invoice | ||
| An updated invoice was issued to correct errors in a previously sent invoice | ||
Other | Additional document types by agreement |
Document header data
Supplier and buyer details
Line items
Tax information
3️⃣ Contact Data Requirements (Buyers & Suppliers)
Accurate contact data is mandatory.
This data is used for:
Addressing and routing (Peppol)
Delivery and notifications
3.1 Mandatory Fields (Per Contact)
| Field | Required |
|---|---|
| Legal name | ✅ |
| Full address (street, city, postal code, country) | ✅ |
| Country code (NZ for domestic suppliers) | ✅ |
| New Zealand Business Number (NZBN) or GST number | ✅ |
| Peppol Participant ID (for routing) | ✅ |
Applies to BOTH customers and suppliers.
3.2 Optional
Trading name
Email address
Phone number
Contact person's name
Department name
Website
Internal reference code
3.3 How to Provide Contact Data
Option A – API
Each contact must be retrievable using a unique identifier
All mandatory fields must be returned
Used to avoid duplicates and ensure correct matching
Option B – CSV Upload
CSV must include all mandatory fields
A unique reference column may be required for create/update logic
Column order and format will be confirmed by Link4
4️⃣ Tax Information
Tax data must comply with the target jurisdiction (e.g. Peppol New Zealand, Peppol VAT rules).
4.1 Mandatory (Header Level)
GST number
Currency = NZD
GST 15%
5️⃣ Line Level Field Requirements
Required
Description
Quantity
Unit of measure
Unit price
Line amount
GST rate (15% or 0%)
GST amount
Optional
Product code
Discount
Service period
PO reference
7️⃣ Document Header Requirements
Mandatory
Unique document number
Issue date (YYYY-MM-DD)
Document type (Invoice / Credit Note)
Supplier details (NZBN or GST number, legal name, full address)
Buyer details (NZBN or GST number, legal name, full address)
Currency (NZD unless otherwise agreed)
Tax-exclusive amount
Total GST amount
Tax-inclusive amount
Optional
Due date
Order reference (PO number)
Buyer reference
Contract or project reference
Payment terms
Bank/payment details
Delivery date
Internal notes (must comply with Peppol format rules)
7️⃣ API Integration Requirements
Authentication
Secure credentials (OAuth or API keys)
Read and write permissions
Data Coverage
Header data
Line items
Tax information
Contact lookup via unique ID
System Behaviour
No Duplicate documents
Clear HTTP errors
Stable identifiers for retries
8️⃣Validation & Submission
All documents are validated against:
Inland Revenue NZ(If any) + Peppol rules
Missing or invalid data may result in:
Document rejection
Validation errors
Delivery failure (e.g. buyer not on the network)
Related Articles
Link4 Integration Guide - Singapore (SG)
Technical Requirements and Mandatory Data ? Purpose This document outlines the mandatory data, technical requirements, and integration expectations for organisations connecting to Link4 to send and receive electronic invoices and related documents. ...Link4 Integration Guide - Belgium (BE)
Technical Requirements and Mandatory Data ? Purpose This guide explains the mandatory technical and data requirements for organizations integrating with Link4 to send and receive electronic invoices. Before integration, ensure your ERP, Accounting ...How to update your Bank Account Number? (NZ Users)
You can update the Bank Details required by your customers when sending your invoices. Please note that the details saved in your Link4 Settings will be sent to your customers along with your eInvoices. The New Zealand bank account number format A ...How to Send an eInvoice through Link4 using Xero? (NZ Users)
Once you have successfully connected your Link4 account with Xero, you can start sending eInvoices to your customers by creating the invoices as you normally do in Xero. Before sending eInvoices, there are a few points to remember : Make sure that ...How to connect your Accounting Software with Link4? (NZ Users)
Step 1 Log in via our website. Step 2 - Select your Accounting Software and follow the prompts. Please note that you will be required to log into your accounting software and authorise Link4 connection. Once connected, you can go to the "My Network" ...