Dental and Orthodontic HST Input Tax Credit Calculator
The 35 per cent shortcut is gone, and a practice claiming input tax credits now needs an allocation it can defend. Work out the zero-rated share of your billings, the credits you can actually recover, what not registering costs you, and the year-end reconciliation the method requires.
recoverable for the year
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Billings by Supply Type
| Supply | Treatment | Amount | Share of Billings | Supports Credits |
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Credits by Input
| Input | HST Paid | Allocation Basis | Recoverable |
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Against the Withdrawn Arrangement
| Basis | Zero-Rated Billings | Commercial Share | Credits |
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Points That Decide This
What to Do Next
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Disclaimer: Most dental services are exempt supplies under Part II of Schedule V to the Excise Tax Act, so no GST/HST is charged on them and no input tax credits arise in respect of them. Orthodontic appliances and dentures are zero-rated under Part II of Schedule VI, meaning tax applies at 0% and the supply is still a taxable supply that supports input tax credits. Purely cosmetic procedures are taxable at the Ontario rate of 13%. Section 141.01 of the Excise Tax Act requires inputs to be apportioned between commercial activity and other purposes using a method that is fair and reasonable, and used consistently throughout the year. The Canada Revenue Agency previously accepted an administrative arrangement under which a fixed percentage of an orthodontic fee was treated as consideration for the zero-rated appliance; this calculator proceeds on the basis, as instructed, that the arrangement was withdrawn with effect from 1 January 2025, and practices must now support their own allocation. Please confirm the current status and effective date of that withdrawal directly with the Canada Revenue Agency or a GST/HST specialist before relying on it. Capital property is subject to separate rules, including the primary use test in section 199 for capital personal property and the rules in sections 206 and 209 for real property, so equipment and leasehold improvements may not follow the general allocation. HST is applied at 13%. This page is general information, not tax advice.
Three Kinds of Supply, and Only Two Give Credits
A dental practice makes supplies that fall into three different GST/HST categories, and the distinction between two of them decides everything about input tax credits.
| Supply | Treatment | Tax Charged | Supports Credits |
|---|---|---|---|
| General dental services | Exempt, Schedule V Part II | None | No |
| Orthodontic appliances | Zero-rated, Schedule VI Part II | 0% | Yes |
| Dentures | Zero-rated, Schedule VI Part II | 0% | Yes |
| Purely cosmetic procedures | Taxable | 13% | Yes |
Exempt and zero-rated look identical to the patient, since neither is charged tax. They are opposites to the practice. An exempt supply gives no right to recover the tax paid on the inputs that produced it. A zero-rated supply is a taxable supply charged at nothing, and it carries the full right of recovery.
That is why orthodontics is worth the administrative effort and general dentistry is not. A practice doing only exempt work recovers nothing and has little reason to register. A practice supplying appliances is giving away real money by staying outside the system.
The Orthodontic Fee Is Two Supplies in One
An orthodontic treatment plan bundles a zero-rated appliance with exempt professional services into a single fee, and the practice has to decide how much of that fee belongs to each. That split drives the allocation, the allocation drives the credits, and the credits are the money.
For years the Canada Revenue Agency accepted an administrative arrangement that treated a fixed percentage of the fee as consideration for the appliance. It was simple, it was consistent across the profession, and nobody had to prove anything. On the basis we have been given, that arrangement no longer applies from 1 January 2025.
Losing the shortcut does not lower the entitlement, it raises the evidence burden. The credits are still available. What has gone is the ability to claim them on a number nobody had to justify. A practice still claiming on the old percentage is claiming on a basis that no longer has administrative backing, and has no file to produce if asked.
What Fair and Reasonable Actually Means
Section 141.01 requires apportionment on a method that is fair and reasonable and used consistently through the year. It does not prescribe a method, which is both the difficulty and the opportunity: a practice whose appliance costs genuinely exceed the old percentage can now claim more, provided it can show the work.
- Direct costing. Lab invoices, appliance materials and the technician time attributable to appliances, measured against the fee. The most defensible where the records exist.
- Chair time analysis. The proportion of clinical time spent on appliance fitting and adjustment against total treatment time.
- Comparable separate pricing. What the appliance would be charged at if supplied on its own.
- Cost plus margin. Appliance cost with a consistent markup, applied across the practice.
Whichever is used, it needs writing down before the claims rather than after the audit letter, and it needs applying the same way to every case for the whole year.
Not Registering Is the Expensive Choice
A practice making only exempt supplies has no obligation to register. Once there are zero-rated appliances in the mix, the position changes, because zero-rated supplies are taxable supplies and they count toward the small supplier threshold as well as supporting recovery.
Practices that never registered, on the reasoning that dentistry is exempt and there is nothing to collect, have usually been absorbing the HST on lab fees, equipment and leasehold improvements for years. None of that is recoverable while unregistered, and registration does not reach backwards except in narrow circumstances.
| Practice Profile | Should It Register | Why |
|---|---|---|
| General dentistry only, no appliances | Usually not worth it | Almost everything is exempt, little to recover |
| Orthodontics or dentures in the mix | Yes | Zero-rated supplies carry full recovery |
| Significant cosmetic work | Yes | Taxable supplies, and registration may be mandatory |
| About to fit out a new clinic | Yes, before the spending | Leaseholds and equipment carry large tax |
Some Inputs Are Traced, Not Allocated
The general allocation applies to inputs used across the whole practice, like rent, utilities and administration. Inputs that can be traced to one kind of supply should be attributed directly instead.
Lab fees for an orthodontic appliance are the clearest case. They relate wholly to the zero-rated supply and are recoverable in full, not at the practice-wide percentage. Applying a blended rate to them understates the claim, and it is one of the most common ways these calculations lose money.
Capital property does not follow the general allocation at all. Capital personal property is governed by a primary use test, so equipment used more than half in commercial activity can attract full recovery while equipment below that line attracts none. Real property and leasehold improvements follow their own rules again. Treating a new chair or a clinic fit-out at the blended percentage is usually wrong in one direction or the other.
The Year-End Reconciliation Is Part of the Method
Claims during the year are made on an estimate, because the year’s actual billing mix is not known until the year has closed. Once it has, the estimate has to be compared against the actual and the difference corrected.
This is not optional tidying. A practice that estimates high and never reconciles has over-claimed, and interest runs on the excess from each period. One that estimates low and never reconciles has simply left money behind. The reconciliation is what makes an estimate defensible in the first place.
Multi-Associate Practices Need Care
Where associates have materially different service mixes, a single practice-wide percentage can misstate the position for all of them. An orthodontist and a general dentist under one roof have very different appliance shares, and a blended figure flatters one and penalises the other.
The structure matters too. Whether associates are employees, independent contractors billing the corporation, or separate professional corporations with cost-sharing arrangements changes who makes which supply and who claims which credit. That has to be settled before the allocation is designed.
What This Calculator Does Not Cover
- Whether a specific procedure is exempt, zero-rated or taxable, which turns on the facts and on the wording of the schedules
- The capital property rules in sections 199, 206 and 209, which override the general allocation
- Associate and cost-sharing structures, which determine who is making the supply
- The public service body rebate, where any part of the practice qualifies
- Change-of-use rules when a practice starts or stops making zero-rated supplies
- Correcting prior periods, where the old arrangement was applied after it ceased to be available
The allocation method is a document you write once and rely on for years, so it is worth building properly. Our accounting service for dentists covers the allocation study, the registration decision, the claim itself and the year-end reconciliation.
Frequently Asked Questions
Common questions on HST for dental and orthodontic practices.
Related Calculators and Guides
More tools for dental and professional practices.
Build the Allocation Before the Next Claim, Not After the Audit
Send us a year of billings split by service, your lab invoices and the equipment and leasehold spending. We will build a documented fair and reasonable allocation, quantify the credits, file the claim and set up the year-end reconciliation so the method holds.