How Do I Connect My Accounting Software to InvoiceNow? A Step-by-Step Peppol Setup Guide (2026)

To connect your accounting software to InvoiceNow, you register your business on the Peppol network through an IMDA-approved Access Point, link that Access Point to your accounting system (either natively or via a connector), map your invoice fields to the Peppol BIS Billing 3.0 standard, and send a test invoice before going live. For most Singapore SMEs on Xero, QuickBooks, or a cloud ERP, this is a half-day setup rather than a project — the complexity is in the details, not the duration. Below is the exact sequence we walk clients through.

What is an Access Point, and why do I need one?

InvoiceNow runs on the international Peppol network, and you cannot send invoices onto Peppol directly from your accounting software. You connect through a Peppol Access Point — an IMDA-accredited service provider that acts as the postal gateway between your system and your customer's system. Think of it as the courier: you write the invoice, the Access Point delivers it onto the network and routes it to the recipient's Access Point.

There are two ways to get one. First, your accounting software may have a built-in Access Point — Xero, for example, offers native InvoiceNow connectivity, as do several local solution providers listed in the IMDA InvoiceNow directory. Second, if your software lacks native support, you subscribe to a standalone Access Point provider and connect it via API or a middleware connector. The native route is simpler for SMEs; the standalone route gives larger or multi-system businesses more control.

How do I register my Peppol ID?

Every business on the network needs a unique Peppol Participant ID. In Singapore, this is built from your UEN — typically in the format 0195:UENXXXXXXXX, where 0195 is Singapore's assigned scheme identifier. You don't generate this yourself; your Access Point registers it on your behalf in the Peppol directory (the SMP/SML lookup system) so other businesses can find and send to you.

The practical steps:

1. Confirm your UEN and registered company details match your ACRA records exactly — mismatches are the most common cause of registration rejection.
2. Sign up with your chosen Access Point and request InvoiceNow (Peppol) registration.
3. The Access Point submits your participant registration and you receive confirmation that your Peppol ID is discoverable.
4. Verify discoverability by asking a peer or your Access Point to look up your UEN in the network directory.

Until your ID is live in the directory, customers cannot send you e-invoices and you cannot send addressed invoices to them — so treat this as the gating step.

How do I link the Access Point to my accounting software?

This is where the path forks by platform:

Xero: Enable e-invoicing in your organisation settings, register your details for InvoiceNow, and Xero handles the Access Point connection natively. Outgoing invoices then carry an "Send via e-invoicing" option.

QuickBooks and other cloud platforms: Check the IMDA pre-approved solution list. If native support exists, follow the in-app activation; if not, connect through a third-party Access Point that offers a QuickBooks connector or API integration.

ERPs (SAP Business One, Microsoft Dynamics, NetSuite, local ERPs): Most connect via an Access Point's API or a certified middleware module. This usually involves your IT partner mapping the ERP's invoice output to the Peppol format and configuring the API credentials.

The principle is the same everywhere: the accounting system remains your source of truth, and the Access Point translates and transmits. You are not migrating data — you are adding a delivery channel.

What invoice fields do I need to map?

Peppol invoices follow the BIS Billing 3.0 standard, and the network rejects invoices that miss mandatory fields. Before go-live, confirm your software is populating each of these correctly:

• Buyer's Peppol ID — you need the recipient's UEN-based participant ID to address the invoice.
• Your seller details — legal name, UEN, and registered address matching ACRA.
• Invoice number, issue date, and currency.
• Line items — description, quantity, unit price, and applicable GST rate per line.
• GST treatment — correct tax category codes, especially important for zero-rated, exempt, or out-of-scope supplies.
• Total amounts — subtotal, GST amount, and grand total, which must reconcile.

The field most SMEs get wrong is GST categorisation, because the human eye forgives a loosely labelled invoice but the Peppol validator does not. Clean this up before you scale.

How do I test before going live?

Never switch your whole customer base over on day one. Run a controlled pilot: pick one friendly customer who is also InvoiceNow-ready, send a single live e-invoice, and confirm three things — that it arrives in their system, that the totals and GST match exactly, and that it reconciles in your own ledger. Then expand in batches.

Keep your existing invoicing method running in parallel during the pilot so nothing falls through. Once you have sent and reconciled a handful of real invoices without manual correction, you can make InvoiceNow your default for any customer who is on the network. This staged rollout is the difference between a smooth transition and a month of finance firefighting.

Frequently Asked Questions

Do I have to connect to InvoiceNow now, or can I wait for the GST mandate?
The IRAS GST e-invoicing requirement is rolling out in phases, starting with newly GST-registered businesses. Even if your phase is later, connecting early means you can receive e-invoices from suppliers who adopt ahead of you, and it removes a deadline scramble. Treat the mandate as a floor, not a target.

Does connecting to InvoiceNow change how I record GST or file with IRAS?
It changes the delivery format, not your accounting treatment. You still record GST and file as usual, but because the data is structured and machine-readable, the medium-term benefit is cleaner records and the eventual potential for more automated reporting. Your chart of accounts and filing cadence stay the same.

What if my customer or supplier isn't on InvoiceNow yet?
You simply continue sending or receiving invoices the conventional way with them, and use InvoiceNow only with network-connected counterparts. There is no all-or-nothing switch — adoption is per relationship, which is exactly why a phased rollout works.

Not sure whether to activate native connectivity in your existing software or run a standalone Access Point — and who maps the fields? That buy-versus-delegate decision is where most SMEs stall. Digital Perpetual sets up InvoiceNow end to end for lean Singapore teams, so your finance function gains a channel without losing a week. Talk to us about your H2 2026 e-invoicing setup.