Why we built Invoicr for your phone, not your office

The desk-bound problem

Most invoicing apps treat mobile as an afterthought. They're designed for accountants in offices, then squeezed onto a phone screen. You tap, scroll, zoom, tap again. It's friction. For tradespeople, that friction costs money. A plumber doesn't have time to sit down and batch invoices three days after a job; an electrician doesn't want to wait until Tuesday to follow up on a payment.

When we started building Invoicr, we made a deliberate choice: mobile first, not mobile friendly. It means the phone isn't a compromise. It's the primary experience. Everything else flows from that decision.

What that actually means in practice

Mobile-first isn't just about button size or vertical layouts. It's about workflow. On Invoicr, you can create and send an invoice in under 30 seconds from anywhere. Take a photo of the work, add a line item, enter the client name from your contacts, hit send. That's it. The app does the maths; it formats it professionally; your client receives it via WhatsApp if you're on Pro, or email if you're on Free.

The bank-to-bank payment link sits right there on the invoice. Your client taps it, authenticates with their own bank using UK open banking, and the money moves to you directly. No card terminal needed. No waiting for Stripe or PayPal to settle. On a £500 job, you're looking at around £4 in payment costs instead of £12.50 with a card processor. That's not a detail; that's money in your pocket.

We didn't add that feature because it was clever. We added it because the lads using Invoicr kept saying the same thing: I don't want to carry a card reader. I don't want to wait five business days for payment. Let me just get paid.

The customer portal story

Early on, we noticed something. Tradespeople wanted clients to see invoices on their own terms, not via email forwarding or WhatsApp screenshots that get lost in chat. But they also didn't want to hand over access to their whole account.

So we built a client portal. It's a secure URL unique to each invoice. No login required; no username to forget. Your client opens the link, sees the invoice, and gets a clear button to pay via their bank. We use token authentication on the backend, which means we're not storing passwords or creating login friction. The client sees what they need to see; nothing else.

That feature came from a conversation with a decorator in Manchester who was tired of clients saying they didn't receive invoices. The portal gave him a way to prove it, and gave clients a clean, branded experience. Everyone won.

The constraint that shaped design

Building genuinely mobile-first meant saying no to things we could easily add. We didn't build a desktop web app, because we knew that would tempt us to dump features there that don't belong on a phone. We didn't build multi-currency support, because our users are UK tradespeople; they need VAT and CIS compliance, not peso conversions. We didn't try to be Xero.

That constraint kept us focused. Every feature had to earn its place on a five-inch screen. No vanity; no bloat. Free tier gives you 5 invoices a month and 3 customers because that's the ceiling where most new sole traders start. Pro unlocks unlimited invoices, payment reminders that actually text your clients, and the ability to send quotes. Business adds team seats, VAT calculations, and an accountant export so your bookkeeper doesn't have to manually re-enter everything.

The constraints aren't limitations. They're anchors.

What we learned from live feedback

Six months in, we had builders, plumbers, electricians, cleaners, and mobile mechanics using Invoicr. One message kept appearing: WhatsApp. Clients were asking why invoices came via email when WhatsApp was where business actually lived. So we built it. On Pro, invoices land in your client's WhatsApp inbox, branded with your business name and logo. Read receipts work. The payment link is right there. We've seen payments come back faster on WhatsApp than email, because clients see it in the app they check twenty times a day.

That's not a guess. That's live data from people running real jobs.

The point of all this

Mobile-first isn't trendy. For us, it's structural. We built Invoicr because we watched people like you lose money to friction: friction in payment processing, friction in invoicing workflows, friction in chasing payments. On a phone, sitting in a van, with a cup of tea in your hand, you shouldn't have to think about your invoicing app. It should just work.

That's what we've been building for.