Why we built bank-to-bank invoice payments instead of card processing

The arithmetic nobody talks about

Card processors take roughly 2.5% of every transaction. On a £500 invoice, that's £12.50 gone before you see a penny. For a plumber running thin margins on each job, or an electrician juggling ten sites a week, those cuts add up fast. A contractor doing twenty invoices a month loses £250 in fees alone.

We started building Invoicr as a simple invoicing app for UK sole traders and tradespeople. But the more we spoke to plumbers, decorators, gardeners, and handymen, the clearer it became: they didn't want another slick invoicing dashboard. They wanted to keep the money they earned.

That's when we looked at UK open banking. It had been sitting there for years, quietly getting better. Two businesses can transfer money directly, bank to bank, without a card network taking a cut. The fee structure is different entirely: flat, predictable, and roughly a third of what card processors charge. On that same £500 invoice, you pay around £4.

Building for the reality of running a one-person operation

When you're a mobile mechanic who books jobs on WhatsApp and invoices on your phone while sat in a van, you don't have time for complexity. You need payment to work the way you think about money: you do the work, the client pays your bank account, and the money arrives without friction.

Bank-to-bank payments via open banking are exactly that. Your client clicks a payment link on their phone, authenticates with their own bank, and the money moves. No card details stored. No payment gateway loaded with fees. No waiting for settlement. It's direct, it's UK-based, and it respects the fact that both of you just want the transaction to happen.

We built Invoicr free for the first 5 invoices a month and 3 customers because we wanted tradespeople to feel the difference themselves. Not read about it. Feel it.

Why we didn't just add card payments and call it done

We could have. Plenty of invoicing apps do. But that would have meant burying the real saving under a choice, a toggle, a "recommended payment method" that nobody reads. We wanted bank-to-bank to be the foundation, not an option you find by accident.

That decision shaped everything else. It meant we had to be specific about who we were building for. Not accountants. Not restaurants. Not SaaS companies selling internationally. UK sole traders and small tradespeople. Plumbers, electricians, builders, gardeners, decorators, consultants, handymen, cleaners, mobile mechanics. People whose clients are also based in the UK and have UK bank accounts.

It meant respecting UK compliance from day one: proper VAT handling, CIS for contractors, the ability to export records for accountants. Not because it's trendy, but because that's the legal world these people operate in.

The things we learned building this on mobile

Most invoicing apps are desktop-first. Ours is iOS native and phone-first because we watched plumbers send invoices from job sites, electricians photograph work and attach it to the record, gardeners manage clients from their truck. A browser on a phone is fine, but a native app that works offline and knows the peculiarities of iOS is better.

We built a client portal with a single URL and token authentication, so you can share a payment link without your customer needing to log in or download anything. They land on your invoice, see what they owe, and pay it straight from their bank. Fifteen seconds, no friction.

The Pro tier added WhatsApp delivery because we realised that's where your clients already are. Not email. Not a notification in an app they don't have. WhatsApp. Send your invoice there, and people actually open it.

What we're not trying to be

We're not a replacement for proper accounting software. If you're running a 20-person operation with complex payroll and multi-location VAT, you need something heavier than Invoicr. We're also not a chasing-debts service. We send reminders; we don't hound clients or use dunning tactics.

And we're emphatically not a card processor hiding behind open banking. Our whole point is that bank-to-bank is cheaper and more direct. That's not an afterthought feature. It's why we exist.