FAQ Heavy Duty for iPhone
Questions people actually ask.
Short answers about how the app works, where your data sits, and what happens when you tap the button.
01 Getting started
Opening the app for the first time.
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Do I need an account?
No. There is no sign-up screen and no login. You open the app, put in your business details once, and start billing. There is no password to lose and no email address to hand over.
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Does it work without internet?
Yes. Writing a document, rendering the PDF and running the reports all happen on the phone. You can invoice in a basement or on a plane with the network off.
A connection is only needed at the moment you email or message a document to a client.
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Is it free?
The app is free to start. There is an optional paid upgrade inside the app if you want it.
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What do I need to run it?
An iPhone running iOS 26. Heavy Duty is a native iOS app.
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Can I run more than one business?
Yes. You can set up several companies in one app. Each one keeps its own numbering, its own logo and its own defaults, so the documents never get mixed up.
02 Invoices and estimates
The paper the client sees.
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Can I send an estimate and turn it into an invoice?
Yes. Quote the job as an estimate. When the client accepts it, one tap turns it into an invoice and carries the line items across, so you do not retype anything.
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Can I use my own logo and colours?
Yes. Add your logo and set the accent colour that drives the headers, rules and totals. You can also rename the field labels to the words your trade uses, and show or hide columns like product code, quantity, unit, tax and discount.
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Can I change the invoice template?
There are 11 templates: Clean, Classic, Modern, Bold, Elegant, Techy, Simple, Trendy, Dynamic, Executive and Minimal. You can switch the template on a document and see the result before you send it.
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Can I reuse the same line items every time?
Two ways. The catalog holds the things you sell — item, materials or service — each with a unit, a price, its tax and a product code, so you pick a line instead of typing it.
For a job that is always the same, save the line items of an invoice as a Document Template, then drop the whole set into a new document in one go.
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What happens if I change an item's price later?
Documents you have already issued keep the price they were issued with. An invoice is a snapshot of what you billed, so editing the catalog never rewrites old paperwork. New documents pick up the new price.
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Can I put my terms on the document?
Yes. Terms and conditions go on the document, and you can add a note to the client on top of that.
03 Money, tax and payments
Totals that add up.
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Can I bill in another currency?
Yes. About 65 currencies are available, and you set the one you bill in.
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How does tax work?
You can apply several taxes to the same document, and choose whether tax is inclusive or exclusive. Inclusive means the tax is already inside the price you typed; exclusive means it is added on top of it. Catalog items can carry their own tax so the right one comes in with the line.
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Can I discount a line, or the whole invoice?
Both. There is a discount per line and a discount on the whole document, plus markup and shipping if you need them.
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Can I record a partial payment?
Yes. Record each payment as it lands, including part of the total. The balance updates and the document shows what is still owed.
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How does an invoice become "paid" or "overdue"?
It is worked out live from the payments recorded against it and its due date. Nothing depends on remembering to flip a switch, so the list is never showing a stale status.
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How do I get paid — what payment details can I show?
Print your payment details on the document itself: bank transfer, PayPal, cheque, or a method you define yourself. The app does not process the payment; the client pays you the way you already get paid, and you record it when it arrives.
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Can I see how the year is going?
Reports show invoiced, paid, outstanding and overdue, with a revenue chart and your top clients and top services, by month, quarter, year or all time.
04 Sending and chasing
Getting it to the client.
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How do I send an invoice?
Open the document and pick how it goes out:
- Messages
- The iOS share sheet, for anything else on the phone
- Or print it on paper
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How do I chase an unpaid invoice?
Set a follow-up reminder on the document so it does not go quiet. The invoice list also filters to unpaid, and overdue is derived from the due date, so you can see at a glance who to ring.
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Can a client keep several contact details?
Yes. A client can hold more than one email address and phone number, tags, separate billing and shipping addresses, notes and a pin on the map.
05 Your data
Where your books live.
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Where is my data?
On your iPhone. Invoices, estimates, clients, catalog items and payments are stored on the device. The app does not upload them anywhere, and there is no account behind them.
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How do I get my data out?
Export a full JSON backup of everything, or a CSV you can import into QuickBooks. Individual documents go out as PDFs. Keep your own copy somewhere safe — nothing is locked in.
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How do I move to a new phone?
Export a JSON backup on the old phone, get the file to the new one, and import it there. Because there is no cloud sync, this is the step that moves your work across — do it before you retire the old handset.
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Is my data backed up if I lose the phone?
Only by whatever you have set up yourself: your own exported JSON backup, or an iPhone backup you already make. The app keeps no copy of your books, so export one now and again.
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Does Heavy Duty do my accounting or file my taxes?
No. It is a billing tool. It writes invoices and estimates, tracks what has been paid, and exports your figures so your accountant or your accounting software can take it from there.
Still stuck on something?
Write to support@getheavyduty.com and tell us what the app did and what you expected. A real person reads it.
Free to start, with an optional paid upgrade. iPhone, iOS 26.