Invoice Koi Free generator

Invoice app for UK trades and sole traders

Professional invoices
from the job.

Quote, invoice and track payments from your phone. Even with no signal.

Get it on Google Play

The iPhone app is coming to the App Store.

See how it works

Draft free, no account needed. Subscribe to send.

An invoice from Nadia Ferreira Studio in Bristol to Halverson Build Co., grouped into strip out, electrical and make good, with VAT at 20% and £3,126.00 due
  • Electricians
  • Plumbers
  • Builders
  • Roofers
  • Carpenters
  • Painters
  • Tilers
  • Flooring fitters
  • Landscapers
  • Cleaners
  • Handymen
  • Locksmiths
  • Mobile mechanics
  • Draft before you pay Set up and draft free. Subscribe to send unlimited invoices. No watermark.
  • No account Start drafting immediately. Sign in for backup or payments.
  • Works offline Create invoices and PDFs in a loft or a cellar.
  • Card payments, if you want them Clients pay through a Stripe link. Payments are recorded automatically.
Why it exists

Send the invoice from the van, not the kitchen table.

Quote, invoice and record expenses before you drive off. Leave the paperwork at the job, and keep the evening for yourself.

A kitchen table late at night covered in receipts, with a calculator, a notebook and a cold mug of tea under one lamp
Before · 10:40 pmThe kitchen table, again.
A tradesperson in the driver's seat of a van at dusk, holding up a phone showing the Invoice Koi invoice list
After · 5:12 pmSent from the driver's seat. Home for dinner.
  • On siteQuote it while they watch.
  • In the vanInvoice sent before you start the engine.
  • At homeNothing. That's the point.

Paper is too little. Field service software is too much.

Invoice Koi is the part in between: the paperwork, without the office.

Paper and a template

  • Tracking unpaid invoices from memory
  • Totals and tax added up by hand
  • Retyping clients for every job
  • A quote written twice, once more as the invoice

Field service software

  • Built around a dispatch office
  • Scheduling, dispatch and CRM tools
  • Plans priced for a team
  • Account setup before invoicing

Invoice Koi

  • Unlimited invoices, no watermark
  • A quote turns into the invoice in one tap
  • Saved clients and your own rates
  • Overdue invoices at a glance
  • No account needed. Works offline.

6:40 pm, Tuesday

Van's parked. Nothing left to type up.

01The invoice

Saved clients and rates
fill in the invoice.

Pick a client, add your saved rates, then send the PDF.

Pick the client. Their address, terms and tax come too.
Tap a rate from your price book. Item, unit and price fill themselves.
Send it as a PDF: by email, or through WhatsApp, Telegram or Messages.
Nadia Ferreira Studio
18 Kiln Lane, Bristol BS3
Invoice
INV–0145
Billed to
Otsuka Interiors
accounts@otsuka-interiors.co.uk
Due · Net 14
17 Sep 2026
Electrical labour
12 hrs × £48.00
£576.00
Plaster and paint, make good
1 room × £320.00
£320.00
Downlight, LED dimmable
10 each × £22.00
£220.00
Subtotal£1,116.00
VAT 20%£223.20
Total due£1,339.20
INV-0145.pdf
  • Telegram
  • Messages
  • Email
Sent
Quote acceptedsigned on the phone
8:15 am, on the doorstep

Quoted on the doorstep. Signed on the glass.

Price the job and collect a signature on your phone. The signature lands on the quote, and the quote becomes the invoice when the job is done.

02What’s in the pond

From the first quote
to the final payment.

An invoice being written: the client at the top, then line items grouped into Strip out and Electrical, each one priced from the price book
Preview

Nine templates, your logo, your accent

Preview the PDF designs your clients receive.

See all nine, side by side
  1. The Kohaku invoice template, printed by the app’s own renderer
    A Kohaku koi: red on white.

    Kohaku

    Red on white

    Letterhead left, title and facts right.

  2. The Sumi invoice template, printed by the app’s own renderer
    A Sumi koi: the ink itself.

    Sumi

    The ink itself

    Minimal layout with a slim accent at the top.

  3. The Asagi invoice template, printed by the app’s own renderer
    A Asagi koi: a blue net, laid straight.

    Asagi

    A blue net, laid straight

    Centred title, with letterhead and facts below.

  4. The Ogon invoice template, printed by the app’s own renderer
    A Ogon koi: one metal, nose to tail.

    Ogon

    One metal, nose to tail

    Bold accent header, with letterhead beneath.

  5. The Tancho invoice template, printed by the app’s own renderer
    A Tancho koi: one red circle, centred.

    Tancho

    One red circle, centred

    Boxed title and facts beside the letterhead.

  6. The Utsuri invoice template, printed by the app’s own renderer
    A Utsuri koi: black answering a second colour.

    Utsuri

    Black answering a second colour

    Left-column letterhead and a ruled table.

  7. The Shusui invoice template, printed by the app’s own renderer
    A Shusui koi: one row of scales, down the spine.

    Shusui

    One row of scales, down the spine

    Centred letterhead, title and facts.

  8. The Goshiki invoice template, printed by the app’s own renderer
    A Goshiki koi: five colours in one fish.

    Goshiki

    Five colours in one fish

    Corner title tab and a panel grouping the totals.

  9. The Chagoi invoice template, printed by the app’s own renderer
    A Chagoi koi: tea brown, and no pattern.

    Chagoi

    Tea brown, and no pattern

    Letterhead on an accent panel.

03 · No signal, no problem

Cellars. Lofts. Crawl spaces. It still works.

Create invoices and PDFs offline. AI, cloud backup and payment collection need an internet connection.

The books are on the phone
Invoices, quotes, clients, the price book and receipt photos stay on your phone.
A backup file you own
Export one backup file. Keep it anywhere and import it on another phone.
An account is optional
Sign in for cloud backup, a second device or payment collection.
Send from your own address
Share the PDF through your own email or messaging app. You choose when to send.
No service · still invoicing
Under a kitchen sink halfway through a repair, with a bucket, a towel and tools on the floor
A tradesperson's hand on a receipt at a builders' merchant counter, beside work gloves and a coffee
Scanned at the counter
04 · Pricing

Draft free.
Subscribe to send.

One subscription. Every feature.

Weekly
Free trial included
£9.99 /week Billed weekly
  • Send unlimited invoices, quotes and receipts
  • Photo backup across devices
  • Unlimited AI scans and voice-to-invoice
  • Priority support in 1 to 2 working days
Get it on Google Play

The iPhone app is coming to the App Store. Notify me at launch

Yearly
Free trial included
£99.99 /year About £8.33 a month, billed yearly
  • Send unlimited invoices, quotes and receipts
  • Photo backup across devices
  • Unlimited AI scans and voice-to-invoice
  • Priority support in 1 to 2 working days
Get it on Google Play

The iPhone app is coming to the App Store. Notify me at launch

Subscribe in the app. On Google Play now. Coming soon to iPhone. Have the app? Open it

UK App Store solo prices. Local prices and offers appear in the app.

Trial, billing & access details

UK App Store solo prices. Prices and offers vary by country and store. Your local price appears in the app before purchase. Eligible new iOS subscribers: two weeks free on annual, one week on weekly. Nothing starts until you confirm the purchase. Without a trial, the displayed price applies immediately. Renews automatically until cancelled in your store account settings.

Existing customers keep their promised core document access. Your issued records remain available after expiry. More about access.

Invoice Koi is on Google Play, and the iPhone app is in App Store review.

Compare invoice apps

Payment fees

Card payments: 0.35% with a subscription, or 0.7% + £0.10 without one, plus Stripe processing fees. Recording payments yourself has no Koi fee.

  • VisaMastercardAmerican Express
  • Apple Pay
  • Google Pay
  • Link
  • Bacs Direct Debit
  • Pay by Bank
  • Klarna
  • Clearpay
  • PayPal

Available through Stripe. Choose which to enable.

05 · Questions

Free to draft. No account.
Works with no signal.

Is Invoice Koi free?

Invoice Koi is free to set up and draft in. Sending invoices, quotes and receipts needs a subscription: £99.99 a year, or £9.99 a week (UK App Store prices). The browser invoice generator is free. See prices and trial terms.

Does it work without a signal?

Yes. Create invoices and PDFs offline. AI, cloud backup and payment collection need an internet connection.

Do I need an account?

No account is needed for core invoicing. Sign in for cloud backup or payment collection. Payments also need Stripe setup; subscriptions use your store account.

What does Invoice Koi run on?

iPhone and iPad, on iOS 16.4 or later. The free invoice generator on this site runs in any browser and needs nothing installed.

Which trades is it for?

Electricians, plumbers, builders, heating engineers, roofers, carpenters and joiners, painters and decorators, plasterers, tilers, flooring, landscaping, cleaning, handyman work and mobile mechanics. See all trades.

Does Koi email my clients?

You send invoice PDFs through your own email or messaging app. Koi records payments collected through it automatically. Record cash and payments received elsewhere yourself.