Laboratory fees are usually one of the largest variable costs in a dental practice, often running at something like 8 to 15 percent of turnover depending on how prosthetic your caseload is. They are a normal, allowable revenue cost, but how you classify them, how you handle the VAT, and how closely you track them as a percentage of revenue all feed directly into your margin and your tax position.
This guide covers where lab fees sit in the accounts, the VAT nuance that catches a lot of practices out, the lab cost percentage as a working KPI, and the practical levers you can pull to keep the cost under control.
Lab fees are an allowable revenue cost
Lab fees paid to an external laboratory for patient work are a straightforward allowable expense for tax purposes. They are revenue in nature, not capital, so the full cost reduces taxable profit in the period it relates to. There is no special relief to claim and no capital allowances question for ordinary external lab work, it is simply a trading cost like materials or staff.
The interesting decisions are about presentation rather than allowability: where in the profit and loss account the cost belongs, and how you read it once it is there.
Cost of sales, not a general overhead
The most useful way to present external lab fees is as a direct cost of sales, sitting immediately below revenue, rather than buried among general overheads further down the page. The reason is the matching principle: a lab fee is incurred to deliver a specific, invoiced treatment, so it belongs against the revenue from that treatment.
Put it in cost of sales and your gross profit reflects the true return after the direct cost of delivering the work. That is the number you actually use to judge whether your fee schedule covers the work behind it. Bury the same fee in overheads and your gross profit looks artificially healthy while your net profit quietly absorbs the hit, which makes pricing problems much harder to spot.
A small subset of lab-related spending is genuinely an overhead and stays out of cost of sales: maintenance on an in-house facility, consumables used for practice administration rather than patient work, and depreciation on any in-house lab equipment. The line to hold is simple: cost of sales tracks revenue, overheads do not.
| Cost | Where it belongs | Why |
|---|---|---|
| External lab fee for a patient crown, bridge or denture | Cost of sales | Directly tied to invoiced treatment revenue |
| In-house lab consumables for patient work | Cost of sales (or materials) | Consumed to deliver chargeable treatment |
| In-house lab equipment maintenance | Overhead | Running cost of the practice, not a single treatment |
| In-house lab equipment (the asset itself) | Capitalised, then depreciated | Capital item written down over its life, with capital allowances on the tax side |
| Technician salary in an in-house lab | Staff costs | An employment cost, not a cost of sales line |
The VAT nuance on dental laboratory work
This is where lab costs are widely misunderstood, so it is worth getting precisely right. Dental care provided by a registered dentist is VAT exempt. Crucially, so is the supply of dental prostheses. Under VATA 1994 Schedule 9 Group 7, the supply of dental prostheses such as crowns, bridges and dentures by a person on the dentists' register, a registered dental care professional, or a registered dental technician is exempt from VAT.
What that means for the bill from your laboratory depends on your lab's own status:
- Where the laboratory or technician is appropriately registered, the supply of the prosthesis to you can itself be exempt. There is then no VAT on the invoice to worry about and nothing to reclaim.
- Where the supplier is not so registered, a commercial laboratory's work may instead be standard rated. The status of a commercial lab can vary, so you cannot assume one treatment for every supplier.
The sting is in what happens when a lab charges you standard-rated VAT. Because your own dental care supplies are exempt, your practice generally makes no taxable supplies to set that input VAT against, so you usually cannot reclaim it. The VAT then sticks to you as a true, unrecoverable cost, and the VAT-inclusive figure is the real cost of the work. This is the opposite of the common assumption that a VAT-registered dental practice simply reclaims VAT on its lab bills.
There is a narrow exception. A practice that also makes taxable supplies, typically purely cosmetic treatment such as tooth whitening or facial aesthetics, is partially exempt and may recover the slice of input VAT attributable to that taxable activity. Even then, lab work for exempt dental treatment remains irrecoverable, and any shared input VAT is split under a partial exemption calculation.
The practical takeaway is to check how your own laboratory treats its supplies and look at the actual invoices. If a lab is charging you standard-rated VAT that you cannot reclaim, that VAT is part of the cost you should be comparing and controlling, not a recoverable add-on. When in doubt, confirm the position with your accountant before assuming either treatment.
Lab cost as a percentage of revenue: a working KPI
Lab cost as a percentage of revenue is one of the cleaner KPIs in a dental practice because it is a direct, mechanical relationship: every prosthetic treatment you invoice carries a lab cost behind it. Tracked over time, the ratio tells you whether your fees are keeping pace with what the lab charges you.
Most practices land somewhere around 8 to 15 percent of turnover, but the band is wide and mix-driven rather than a target in itself. A book heavy with implants, complex restorative work and cosmetic cases will sit at the upper end and beyond, while a practice dominated by examinations, hygiene and routine NHS bands will sit lower. The number on its own says little. The trend says everything.
Read the movement, not the snapshot. A creeping percentage against a static fee schedule means lab prices have risen and your fees have not followed, so margin is leaking on every unit. An unusually low percentage is not automatically good either, it can simply mean you refer most lab-based work elsewhere and are leaving higher-margin treatment on the table. Either way, the ratio is most useful reviewed monthly or quarterly alongside your gross margin, which is one reason it pays to understand how to read a dental practice profit and loss account and see how the lab line drives the gross profit figure above it.
Control levers: managing the materials and lab mix
Lab cost is one of the more controllable lines in the accounts, because you influence both the price you pay and the volume of work you send out. The levers fall into a few groups.
Digital workflow
Intraoral scanning and digital impressions reduce remakes from poor physical impressions, and remakes are pure cost with no offsetting fee. Digital workflows can also open up more competitive lab options, including remote labs, because the file travels instantly rather than a physical impression being couriered. The trade-off is the upfront investment in the scanner, which is a capital decision with its own allowances, so weigh it against your actual prosthetic volume rather than buying on enthusiasm.
Lab selection and the materials mix
The choice of laboratory and the materials you specify drive most of the cost. Consolidating work with one or two trusted labs can earn better terms and more consistent quality, which itself cuts remakes. Matching the material to the clinical need rather than defaulting to the premium option on every case keeps the average cost down without compromising care. Reviewing lab invoices regularly also catches billing errors and scope creep before they become the norm. And, as covered above, factor in whether a given lab's VAT treatment leaves you with irrecoverable VAT, because that changes the true comparison between suppliers.
Who bears the cost in associate splits
On associate work, the lab fee has to land somewhere, and the associate agreement should say exactly where. The common arrangement is to deduct the lab fee before applying the percentage split, so both the practice and the associate share the cost in line with the split. Some agreements instead pass the full lab cost to the associate. Either is workable, but it must be explicit in the contract, because it materially changes the associate's real earnings and how the cost flows through the practice accounts. An unclear or unspoken arrangement is a recurring source of friction and disputes.
In-house versus external labs
Some practices bring lab work in-house, often alongside same-day CAD/CAM restorations. The accounting changes shape entirely. The equipment is capitalised and depreciated, with capital allowances claimed on the tax side. Materials are consumables expensed as used. A technician's pay is a staff cost, and maintenance is an overhead. None of that is cost of sales in the way an external invoice is.
The decision is driven by volume. Above a meaningful throughput of units, an in-house facility can beat external fees once the equipment is paid down. Below that, external labs almost always offer better value once you account for the equipment, the technician and the running costs. The in-house lab line also interacts with your wider cost base, so it is worth viewing through the same lens as your other fixed costs, which is the focus of our guide to dental practice overhead costs management and control.
The bottom line
Lab fees are an allowable revenue cost, but treating them as just another bill leaves money on the table. Classify them as cost of sales so your gross margin tells the truth. Check your laboratory's VAT treatment, because standard-rated lab work is usually an unrecoverable cost for an exempt practice rather than reclaimable VAT. Track the lab cost percentage as a trend against your fees. And use the control levers, digital workflow, lab and materials selection, and clear associate terms, to protect the margin. If you are unsure how the VAT position or the classification applies to your own practice, a specialist dental accountant can confirm the treatment that fits your setup.