InvoiceNow Is Now Law: What Every GST-Registered Interior Design Firm in Singapore Needs to Know

If you run an interior design or renovation firm in Singapore and you're GST-registered, there's a government compliance change underway that most business owners haven't heard of yet — and the first deadlines have already passed.

This post covers everything you need to know: what InvoiceNow is, when it applies to you, why most ID firms are structurally unprepared for it, and how Senquel was built specifically to solve this.

What is InvoiceNow (Peppol)?

InvoiceNow is Singapore's national e-invoicing network, operated by IMDA and mandated by IRAS. It's built on Peppol — an international standard that Singapore adopted in 2018, becoming the first country outside Europe to join the network.

In plain terms: IRAS now requires GST-registered businesses to transmit invoice data through this network in a structured, machine-readable format — not a PDF, not a Word document, not a screenshot sent over WhatsApp. A structured e-invoice that flows directly to IRAS at the time of issuance.

This is on top of your existing GST filing obligations. It's a change to how invoices are created and sent, not just how you file returns at the end of the quarter.

The full rollout timeline

The mandate is being phased in by firm size and registration type. Here's the complete schedule:

• May 2025: Voluntary submission opens. Businesses can start transmitting invoice data early — early adopters received a S$5,000 grant.
• 1 November 2025 (LIVE NOW): Mandatory for businesses newly incorporated within 6 months of applying for voluntary GST registration.
• 1 April 2026 (IMMINENT): Mandatory for all new voluntary GST registrants, regardless of incorporation date. If you're registering for GST from this point onward, InvoiceNow is a condition of registration.
• 1 April 2028: Mandatory for all new compulsory GST registrants, and for existing businesses with annual taxable supplies of S$200,000 or less. This is the deadline that covers the majority of boutique ID and renovation firms in Singapore.
• 1 April 2029: Mandatory for existing businesses with annual supplies up to S$1,000,000.
• 1 April 2030: Mandatory for existing businesses with annual supplies up to S$4,000,000.
• 1 April 2031: Full mandate — every GST-registered business in Singapore, no exceptions.

IRAS has confirmed they will notify businesses of their specific go-live dates by mid-2026. But waiting for that letter is not a strategy — the back-office preparation required takes time, and the firms that act early are the ones who end up compliant without scrambling.

Why most ID firms are unprepared

The honest answer is that most interior design firms in Singapore were never running the kind of back-office that InvoiceNow requires — Peppol just makes that gap impossible to ignore.

The typical workflow: milestones tracked in WhatsApp groups, invoices generated in Word or Excel, PDFs emailed to clients, and reconciliation handled by an accountant in Xero at month-end. That entire chain is non-compliant under InvoiceNow. There is no structured data, no PINT-SG format, and no IRAS transmission happening anywhere in it.

The common assumption is: "My accountant uses Xero — Xero will handle it." This is not correct. Xero is not automatically InvoiceNow-ready. The structured invoice needs to be generated and transmitted to IRAS at the moment of issuance, through an InvoiceNow-ready solution, before it ever reaches your accountant's reconciliation workflow.

There's also the underlying business problem that Peppol simply accelerates. Late milestone payments — typically 21+ days from invoice — compress cash flow at exactly the moment when supplier deposits and contractor payments are due. Supplier orders tracked by WhatsApp message create disputes with no document of record. The 97% of ID firms that remain unaccredited by CaseTrust share one root cause: the back-office was never properly structured in the first place.

How Senquel is built for this

Senquel is an AI-powered back-office platform designed specifically for Singapore interior design and renovation firms. We didn't build an accounting tool and add Peppol as a checkbox — we built the system that makes InvoiceNow compliance possible in the first place.

Here's how the pieces connect:

• Milestone Billing Engine: Projects are structured around milestones from day one. Every completion is timestamped, client sign-off is captured, and the payment trail is audit-ready. No more milestones living in a WhatsApp chat.
• GST-Compliant Invoice Generation: On milestone completion, Senquel automatically generates a structured, GST-compliant invoice — correct category codes applied, PINT-SG format, built for the InvoiceNow transmission pathway. Not a PDF.
• WhatsApp-Native Project Log: Every message, photo, and approval automatically becomes part of the time-stamped project record. The communication your team is already doing becomes your audit trail.
• Supplier PO Tracking: Purchase orders generated directly from material lists, with delivery status tracked per project. The informal WhatsApp orders get replaced with a formal document of record.
• Xero Handoff: Completed invoices sync to Xero automatically. Your accountant's reconciliation workflow doesn't change — they just receive clean, structured data instead of manually entered PDFs.
• CaseTrust-Ready Documentation: Compliant contracts, progress reports, and client sign-off forms auto-generated from project data — the documentation that 97% of ID firms currently can't produce.

The framing we'd offer: Senquel is not "the InvoiceNow solution." It's the back-office you need to be running before InvoiceNow compliance is even possible. The milestone tracker, the project log, the structured invoice — those exist because your business needs them, regardless of any government mandate. Peppol compliance becomes straightforward because the infrastructure is already in place.

For eligible SMEs, the Productivity Solutions Grant (PSG) can cover 50% of qualifying software subscription costs. IMDA is also offering free InvoiceNow-ready solutions until March 2031. Getting compliant doesn't have to mean a major upfront cost.

Security and data protection

We want to be transparent about how we handle your project data, because we know how sensitive client information and financial records are in this industry.

Senquel is built on Supabase, with Row Level Security (RLS) enforced at the database level. Every firm's data is isolated behind firm-scoped access policies — your projects, milestones, invoices, and client records are only accessible to authenticated members of your firm. Not to us. Not to other firms on the platform.

All data is encrypted in transit (TLS) and at rest. Authentication is handled via Google or GitHub OAuth — we do not store passwords. API routes that interact with sensitive data use service-role access only where absolutely required, scoped to the minimum necessary operation.

We do not use your firm's data to train models, improve algorithms, or benchmark against other firms. Your project records are yours. We process them to power the features you've signed up for — nothing else.

Our confidentiality policy: no firm has an advantage over another

This deserves its own section, because it's a principle we take seriously.

Senquel serves multiple interior design firms in Singapore. By definition, some of those firms compete with each other — for the same clients, the same projects, the same market. We are in a position of trust with all of them simultaneously.

Our policy is straightforward: no firm on Senquel receives any information about, derived from, or influenced by the data of any other firm. Specifically:

• We do not share client names, project scopes, contract values, or pricing between firms — ever, in any form.
• We do not produce benchmarks, averages, or market comparisons from aggregated firm data.
• We do not use insights from one firm's project patterns, pricing, or client behaviour to inform features or recommendations shown to a competing firm.
• Our support and engineering teams access firm data only when required to resolve a support issue, always with the minimum access necessary, and never across firm boundaries simultaneously.

If you are considering Senquel and another firm you know is already on the platform, you will not be disadvantaged — and neither will they. The platform is a tool, not a competitive intelligence service. That distinction is non-negotiable for us.

What to do next

If your firm is GST-registered and you're currently invoicing via Word, Excel, or any non-InvoiceNow-ready tool, the window to act is open now. The April 2028 deadline for boutique firms sounds far away — it's 23 months. Onboarding, process change, and staff training take time. The firms that wait until mid-2027 to start will be rushing.

If you'd like to see how Senquel fits your specific workflow, visit senquel.com or reach out directly on WhatsApp at +65 9678 2245. No slides — just a 30-minute walkthrough of how your firm currently handles invoicing and project management, and an honest assessment of whether we're the right fit.