E-invoicing is coming. Mandatory for UK VAT-registered businesses from April 2029, following a decentralised Peppol-aligned model. Accounting firms know this. Most are already fielding questions from clients about what it means for their processes. Here’s the part that doesn’t get said: e-invoicing solves part of the problem. Not all of it. If you’re advising clients or running AP workflows for multiple entities, the part it doesn’t solve is the part keeping your team occupied every day.
Why e-invoicing is actually useful
Structured invoices that move directly between financial systems, with no human re-keying anything, are a real improvement. When a supplier sends a Peppol-compliant invoice and it lands ready-to-post in Xero or QuickBooks Online, that is cleaner than what most firms run today. No manual entry, no chasing email threads, no transcription mistakes.
The government’s case for the mandate holds up. Better cash flow visibility, fewer late payments, less admin overhead. If most of your clients’ suppliers move to structured invoicing over the next few years, a real chunk of the capture work goes away. But most is not all. And the gap between most and all is where accounting firms actually spend their time.
The documents that won’t become e-invoices
Think about what a typical SME client buys in a month. There’s the Shopify subscription, the Adobe licence, the AWS bill, the Zoom renewal. All sent as PDF receipts by US companies with no obligation to adopt UK e-invoicing standards, and no real incentive to rebuild their billing infrastructure. Not before 2029. Probably not after, either. There’s the fuel card statement. The restaurant receipts from the team lunch. The Amazon Business orders. The one-off supplier in Germany who emails a scanned invoice as a JPG. The freelancer who sends a Word document with a BACS reference at the bottom. And then there are the clients themselves. The ones who pay for things by card and forget to forward anything. And the ones with three people submitting expenses from their phones in three different ways. The ones whose supplier portal requires a login every time and produces a download that still needs naming, filing, and processing by someone. None of that becomes a clean Peppol document in 2029. Some of it never will.
What actually changes for accounting firms
The shape of the problem shifts. It doesn’t go away. Right now, accounting firms handle a mixed pile: some documents are decent quality PDFs from regular suppliers, some are photos of receipts or forwarded email chains, and some sit in between. HTML email receipts from SaaS platforms. Excel exports from marketplace accounts. After 2029, that pile gets a new category at the top: properly structured e-invoices from larger UK suppliers. Those flow in cleanly. Good. But everything else is still there. The pile didn’t shrink. It just got sorted differently. The worst outcome is running two parallel workflows: one for e-invoices, one for everything else. Two systems to check, two processes to train staff on, two places for things to slip through.
The question worth asking before the mandate arrives
The firms that will handle 2029 without drama are the ones already asking: how do we build one workflow that handles every document, regardless of format? Because the documents keep arriving in different shapes. Structured data. PDFs. Receipts. Files that need line items broken out. Purchases that need approval before they go near the ledger. Things that come in by email, by upload, by photo from someone’s phone. The accounting team needs one answer for all of them: is this ready for the books?
How Datamolino fits into this
Datamolino captures supplier documents in whatever format they arrive. PDF, TIFF, JPG, email attachment, HTML receipt. It produces structured data ready to export to Xero, QuickBooks Online, or FreeAgent. Documents come in through web upload, email forwarding, or the mobile app. Datamolino processes them, pulls out the header data and line items, applies any rules set up for recurring suppliers, and puts everything in a review queue before anything goes to the accounting software. The firm stays in control of what goes out and when. As e-invoicing adoption grows, the document mix changes. But the need for one place where everything becomes accounting-ready doesn’t. Datamolino handles the documents that structured invoicing doesn’t cover, without creating a separate process for them.
What to do
You have time. The government’s detailed implementation roadmap and technical standards are due at the Autumn Budget 2026. The mandate itself doesn’t land until April 2029.
But the firms that handle the transition without scrambling will be the ones that already had a working document workflow before e-invoicing arrived. Not because Peppol demands it, but because a workflow that handles messy documents reliably also handles clean ones easily. The structured invoices slot in. The rest keeps moving. If the current process relies on email inboxes, shared drives, and whoever happens to know where things live, that’s worth fixing now. Independently of what happens with e-invoicing. 2029 will be hybrid AP: some clean structured data, some document capture, some human review. That’s also what good AP looks like today. The firms that figure that out early won’t notice much of a difference when the mandate arrives.