The short answer
An invoice needs your name and contact details, the client's name, a unique invoice number and date, each service with its date and price, the total, a due date, and how to pay (for example your e-Transfer email).
Registered for GST/HST? From $100 the CRA expects your GST/HST number and the tax shown; from $500, also the client's name, a description and your payment terms. Rules as of September 2026.
Deciding how clients should pay you?
With Biller, every invoice shows your e-Transfer details and, once you connect Stripe, a pay-by-card button — so clients pay the way they prefer, and card payments and Autodeposit e-Transfers are recorded as they land.
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Just need one now? The free invoice generator builds a PDF invoice in your browser, with GST/HST by province and e-Transfer instructions, and no account.
How to write an invoice in 9 steps
- Put your business details at the top. Your legal name, or your registered business name if you have one (see registering in Ontario, BC or Alberta), plus email, phone and a mailing address or city.
- Add the client's details. Their name, and address if you have it. Required by the CRA only at $500 and up if you charge GST/HST, but it's good practice on every invoice.
- Give it a number. Unique and sequential: 1001, 1002, 1003. More on numbering below.
- Date it, and add the due date right beside it.
- List each service on its own line: what you did, the date or date range, the quantity (visits, hours) and the rate. "12 x 30-minute walks, Oct 1 to 16, at $25" answers the client's questions before they ask.
- Add the subtotal.
- Add GST/HST only if you're registered, with your GST/HST number. If you're a small supplier under the $30,000 threshold, leave both off. Charging GST/HST without being registered isn't allowed. The business number guide explains when you have to register.
- Show the total due, bigger than everything else.
- Say how to pay: your e-Transfer email, whether you have Autodeposit, a card payment link if you take cards, and your terms.
An annotated example invoice
A sole proprietor walking dogs in Ottawa, registered for HST because she passed $30,000, bills a regular client for the first half of October. The notes on the right explain each line.
| On the invoice | Why it's there |
|---|---|
| Maple Paws Dog Walking Priya Sandhu, Ottawa ON priya@example.ca · 613-555-0147 | Your business or trade name and contact details. The CRA requires the name on every invoice when you charge GST/HST. |
| GST/HST no. 123456789 RT0001 | Your BN plus RT0001. Required from $100 when you charge HST. Leave it off if you aren't registered. |
| Bill to: Alex Martin, 42 Elm St, Ottawa ON | The client. Required by the CRA at $500 and up; always useful. |
| Invoice #1047 Date: October 16, 2026 Due: October 31, 2026 (Net 15) | A unique number, the invoice date (required), and a due date the client can't misread. |
| 12 x 30-minute walks, Oct 1 to 16, at $25.00 $300.00 | What, when, how many, at what rate. A brief description is required at $500 and up; clear lines prevent questions at any amount. |
| 3 x cat drop-in visits, Oct 10 to 12, at $30.00 $90.00 | One line per kind of service. |
| Subtotal $390.00 | Before tax. |
| HST (13%) $50.70 | The tax charged, shown separately. Ontario is 13% HST; the rate follows where the client is. |
| Total due $440.70 | The total amount payable, required on every invoice. |
| How to pay: Interac e-Transfer to pay@maplepaws.ca (Autodeposit, no security question). Put "1047" in the message. Payable within 15 days. Overdue balances bear interest at 1.5% per month, compounded monthly (19.56% per year). | Payment instructions and terms. The yearly rate is there because the Interest Act requires it when you quote a monthly rate. |
At $440.70 this invoice is in the $100 to $499.99 tier, so the GST/HST number and the tax line are what the client needs to claim an input tax credit. The client's name and payment terms become required once an invoice reaches $500. If she weren't registered, the invoice would stop at the $390.00 subtotal, with no HST line and no number.
What the CRA requires when you charge GST/HST
The CRA doesn't prescribe an invoice format for a small supplier who doesn't charge GST/HST. Once you're registered, your clients who are businesses need specific details to claim an input tax credit (ITC), and the tier depends on the total amount paid or payable. From the CRA's input tax credit information requirements, checked September 2026:
| Total of the sale | What the invoice must show |
|---|---|
| Under $100 | Your business name (or trade name); the invoice date, or the date the tax was paid or payable; the total amount paid or payable. |
| $100 to $499.99 | Everything above, plus your GST/HST registration number; the GST/HST charged, as an amount or rate, or a statement that the price includes it; and which items are taxable if some aren't. |
| $500 or more | Everything above, plus the client's name (or trade name); a brief description of what you supplied; and the terms of payment. |
Thresholds of $100 and $500 have applied since 2021 (they replaced $30 and $150). Older guides and templates still quote the old numbers.
Households can't claim ITCs, so for a dog walker whose clients are families, this matters less day to day. It matters when a client is a business, a property manager or another registrant, and it's simplest to put everything on every invoice. The GST/HST guide covers rates by province and the $30,000 threshold.
Invoice numbering
- Unique and in sequence. Never reuse a number. If you void an invoice, keep the number as void rather than filling the gap.
- Start wherever you like. 1001 looks more established than 1, and nobody minds.
- A prefix is optional. "2026-014" restarts each year; "MP-1047" adds your initials. Pick one scheme and keep it.
- Ask clients to quote it. Put the number in your payment instructions so it comes back in the e-Transfer message, and you know which invoice was paid.
Payment terms that get you paid
Terms tell the client when the money is due. The common ones:
- Due on receipt: for one-off jobs and new clients.
- Net 7 or Net 15: due 7 or 15 days after the invoice date. Good for regular household clients billed weekly or twice a month.
- Net 30: common with businesses and property managers. Longer terms mean waiting longer for your money, so only offer them where clients expect them.
Write the actual date ("Due October 31, 2026") next to the terms. "Net 15" is easy to ignore; a date isn't. Invoicing promptly helps as much as short terms: bill when the job's done, or on a fixed schedule for regulars.
Putting e-Transfer details on an invoice
Most Canadian households pay small businesses by Interac e-Transfer, so make it effortless:
- The email address to send to, exactly as registered with your bank.
- Whether Autodeposit is on. If it is, say "no security question needed." If it isn't, don't put the answer on the invoice; send it separately.
- What to write in the message, ideally the invoice number.
- The name clients will see, if it's different from your business name, so they don't worry they're paying a stranger.
Offering cards too? Add a pay-by-card link, and consider building the processing cost into your rates. The pricing guides show what Canadian service businesses charge.
When an invoice is late
- A friendly reminder a day or two after the due date. Most late payments are forgotten, not refused.
- A second reminder a week later, with the invoice attached again.
- A phone call, and pausing future bookings until the balance is paid.
- Late fees or interest, only if the client agreed to them in advance. If you quote a monthly rate, section 4 of the Interest Act requires you to state the equivalent yearly rate; otherwise you can't recover more than 5% a year.
- Small claims court, for the rare client who won't pay at all. Keep the invoice, your reminders and any messages.
Keeping your invoices
Your invoices are the record behind the income you report on Form T2125. The CRA says you generally must keep records "for a period of six years from the end of the last tax year they relate to." Digital copies are fine. To see what your invoiced income means for tax and CPP, try the self-employed tax calculator.
When a client pays, a paid invoice usually works as their receipt. If someone needs a separate one, for cash, say, the free receipt generator makes a PDF receipt with an optional GST/HST breakdown.
Common questions
What should be on an invoice in Canada?
Your business name and contact details, the client's name, an invoice number and date, a description of each service with the date, quantity and price, the subtotal, any GST/HST with your registration number, the total, the due date, and how to pay. If you're registered for GST/HST, the CRA also expects certain details depending on the amount, so your clients can claim input tax credits.
How do I write an invoice as a sole proprietor?
Use your own name, or your registered business name if you have one, with your contact details. List what you did, when, and for how much, add GST/HST only if you're registered for it, then give a due date and payment instructions. You don't need a business number to invoice; you only need one once you register for a CRA program account such as GST/HST.
Do I have to charge GST/HST on my invoices?
Only if you're registered. You have to register once your taxable sales pass $30,000 in a single calendar quarter or over four consecutive calendar quarters. Until then you're a small supplier: don't add GST/HST and don't put a GST/HST number on your invoices.
Does an invoice need an invoice number in Canada?
The CRA's input tax credit rules don't list an invoice number as a required item. Every invoicing guide and accountant will still tell you to use one: a unique, sequential number makes invoices easy to find, match to payments and reference when a client pays by e-Transfer.
Can I charge interest on late invoices in Canada?
Yes, if the client agreed to it before the work, usually through your terms on a quote or the invoice. Under section 4 of the federal Interest Act, if you state a rate per month (like 1.5% per month), you must also state the equivalent yearly rate, or you can't charge more than 5% a year.
How long do I have to keep copies of my invoices?
The CRA says you generally must keep records and supporting documents for six years from the end of the last tax year they relate to. A digital copy is fine.
What's the difference between an invoice and a receipt?
An invoice asks for payment. A receipt confirms you were paid. Many small businesses mark a paid invoice as paid and send it as the receipt; the free receipt generator makes a standalone one if a client needs it.