Invoice apps for Shopify, compared honestly
FlatInvoice vs Sufio vs Order Printer Pro vs Shopify's free Order Printer — real plans, real features.
Every one of these apps turns a Shopify (the platform many online stores run on) order into a PDF invoice or packing slip. The differences are how much accounting/compliance depth you need, and how much setup time you're willing to spend. Here's where each one actually wins — see each app's own listing for its current plans.
| Factor | FlatInvoice | Sufio | Order Printer Pro | Order Printer (free, Shopify) |
|---|---|---|---|---|
| Plans | See the listing | See the listing | See the listing — free to install | Free |
| Free trial | 7 days | 14 days | 14 days | N/A — free |
| Setup | Business details, accent color, VAT/GST registration + gap-free sequential invoice numbers — one click | Full invoice builder, tax/VAT rules, multi-currency | Template builder, PDF customization | Basic templates, needs Liquid edits to customize |
| Compliance / e-invoicing | Sequential (gap-free) invoice numbers + your VAT/GST registration on every PDF; no PEPPOL e-invoicing | PEPPOL e-invoicing, EU VAT compliance built in | Peppol e-invoicing compliance available as an in-app add-on | None — bare-bones template |
| Auto-email invoices to customers | Yes — on by default for a new install, one toggle to turn off or switch to fire on fulfillment instead | Yes | Yes — automated PDF invoices on every plan, including free | No — manual print/export |
| Theme/code needed | No | No | No | Yes, for real customization |
| Track record | New (2026) | 4.9/5, established | 4.9/5, established | Built by Shopify — 3.5/5, 376 reviews (read September 26, 2026) |
| Best for | Merchants who want it done and forgotten | Businesses needing EU e-invoicing/VAT compliance | Merchants who want deep template control without an EU-compliance need | Anyone comfortable editing Liquid for a free, basic invoice |
Where we lose, and why merchants still pick us
If you sell into the EU and need PEPPOL e-invoicing or VAT compliance, Sufio is the correct answer — that's a real feature gap we don't fill. If you want deep template control without paying for compliance you don't need, Order Printer Pro is worth trying first (its free plan already includes automated PDF invoices, with a Peppol e-invoicing add-on available in-app). And if you're comfortable in Liquid, Shopify's own free Order Printer costs nothing.
FlatInvoice is for the merchant who wants a professional invoice/packing slip live in one click — business name, logo, accent color, gap-free sequential invoice numbers (INV-0001…), your VAT/GST registration on every PDF, and invoices emailed to customers automatically by default — without opening a template editor. We're new, and we don't do PEPPOL e-invoicing. If you need that, use Sufio.
Common questions
Does FlatInvoice support VAT?
Yes — add your VAT/GST registration number and choose a Tax/VAT/GST label, and both appear on every PDF, alongside gap-free sequential invoice numbers (INV-0001, INV-0002…). What it does not do is PEPPOL e-invoicing — if you need that EU compliance standard, Sufio is built for it.
Can it email invoices to customers automatically?
Yes — this is on by default for a new install. Every customer gets their PDF invoice by email when the order is placed; you can switch that to send on fulfillment instead, or turn it off entirely.
Is there a free option?
Shopify's own Order Printer app is free but basic and usually needs Liquid template edits to look professional. FlatInvoice has a free trial and no editing is required.
How long does setup take?
A few minutes — enter your business details, pick an accent color, set your tax label, and every order after that generates a matching PDF.
Does it work with existing order data?
Yes — every new order gets invoiced automatically, and any order from the last 60 days can also be invoiced in one click; no bulk import needed.
Does FlatInvoice generate a 'tax invoice' document?
No — there is no separate 'tax invoice' document type. FlatInvoice generates one PDF invoice per order, with your VAT/GST registration number and label printed on it when you've added one.
Clean PDF invoices from any order, sent automatically. Zero setup.
Install FlatInvoiceWhere a Stelar Digital app (FlatInvoice, Low Stock Alerts & Notify Me, Stockyard, Aivis or Restockly) appears on this page, it is ours; the advice stands whether you use it or not. Features and ratings for other apps reflect their public Shopify App Store listings at time of writing and may change.