Working Capital and Tax Loans: Funding a Dental Practice's HMRC Bills

It surprises many practice owners that a thoroughly profitable dental business can still be short of cash the very month a large HMRC bill falls due. The reason is timing, not profit. A practice pays staff, rent and laboratory bills steadily through the year, while its largest tax liabilities arrive in a few heavy lumps: a January income tax payment on account, a corporation tax bill nine months after the year end, a VAT quarter for the minority of practices that pay VAT, and, for NHS practices, a year-end clawback. When one of those lands in a seasonally quiet month, even a healthy practice can need to borrow to bridge the gap.

This page covers one narrow job: funding the tax and VAT bills themselves. It is not a general working-capital guide, and it does not re-explain overdrafts, revolving credit or VAT-loan mechanics in depth, our companion pages own those and are linked below. Here the question is specific: which short-term facility fits which HMRC liability, when borrowing is the right answer, and when it is the wrong one. The tax treatment is kept to a summary with cross-links, because the lending decision, not the tax computation, is the subject.

Why even a profitable practice needs to fund its tax bills

Profit and cash timing are different things. A practice can be comfortably profitable across a full year and still meet a single month where a large tax payment, a quiet trading period and the usual fixed costs all coincide. Tax bills are the sharpest example of this because they are large, infrequent and, unlike routine costs, do not spread themselves evenly across the year. The practice earns the profit steadily but hands a chunk of it to HMRC on a handful of fixed dates.

Reserving for tax through a rolling cash forecast is the first-best answer, and a practice that sets money aside for each liability as profit is earned rarely needs to borrow at all. That reserving discipline sits within broader cash-flow planning, which our guide to cash-flow management and tax reserves covers in detail. Where a reserve falls short, because the bill is larger than expected, the month is unusually quiet, or cash went on a genuine priority like equipment, a short-term facility bridges the gap until income catches up. That is the legitimate role of borrowing here: a deductible bridge over a timing gap in an otherwise healthy practice, matched to a bill the practice can see and to income that is genuinely coming.

The three lumpy liabilities (and the NHS one)

Three tax liabilities create most of the pinch points, plus a fourth NHS-specific one that behaves the same way in cash terms.

Income tax payments on account

A self-employed associate or an unincorporated principal pays income tax through Self Assessment in two payments on account, due 31 January and 31 July, each broadly half of the prior year's liability, with a balancing payment the following 31 January (see the gov.uk payments-on-account guidance). The 31 January date is the classic squeeze: it combines the balancing payment for the year just filed with the first payment on account for the next, often in a post-Christmas month when patient bookings are thin. A profitable associate can still be cash-short that month. The self-employment position of associates, and how it drives this liability, is covered in our associate tax survival guide.

Corporation tax

An incorporated practice pays corporation tax nine months and one day after its accounting year end (gov.uk corporation tax payment). For 2026/27 the rate is 19% on profits up to £50,000, 25% above £250,000, with marginal relief between, so a mid-sized dental company sits in the marginal band and a full year's tax can be a substantial single payment. The date is fixed and foreseeable, which makes reserving straightforward in principle but the bill no smaller when it lands.

The VAT quarter

Most dental practices pay no VAT at all, because dental treatment by a GDC-registered dentist is exempt under VATA 1994 Schedule 9 Group 7 and does not count toward the £90,000 registration threshold. Only mixed or cosmetic-heavy practices with standard-rated turnover above the threshold, or partially exempt practices facing a Capital Goods Scheme adjustment, have a real VAT bill. For those that do, the quarterly payment is due one month and seven days after the quarter end. The full mechanics, penalty arithmetic and the choice between a VAT loan and HMRC Time to Pay are on our dedicated VAT loan for dental practices page, and this page does not repeat them.

NHS clawback (not a tax, but the same cash shape)

For NHS practices, a year-end reconciliation that finds UDA delivery below the contracted threshold triggers a clawback: a lump-sum recovery of contract value, administered through the NHS Business Services Authority, often recovered months after the income was received and spent. It is not an HMRC liability, but in cash terms it is another large, dateable outflow that can need bridging on exactly the same logic as a tax bill.

Tax loans and VAT loans: what they are and when they fit

A tax loan is a short-term, purpose-specific facility drawn to fund a defined liability, a payment on account, a corporation tax bill or a VAT quarter, then repaid from trading income over roughly three to twelve months. The lender either advances the funds to the practice or pays HMRC directly. Its defining feature is that it is self-liquidating: matched to one known bill and one repayment cycle, it clears itself and does not roll into the next liability. A VAT loan is simply the VAT-specific version of the same product, sized to the net quarterly VAT payable.

The operational advantage of a dedicated tax loan over using the general overdraft for the same purpose is discipline. The loan is drawn for one bill, repaid on a defined timetable, and does not permanently consume the overdraft headroom the practice relies on for day-to-day cash. It also makes the cost of each HMRC bill a discrete, visible line item rather than a generalised overdraft balance that grows and shrinks unpredictably. If a practice already carries a high overdraft utilisation, a separate tax facility avoids compounding that position.

When a general working-capital facility is the better tool instead

A tax loan is the right instrument for a single, dateable bill. It is the wrong instrument for a small, frequent, unpredictable cash gap, where a flexible facility fits far better. An overdraft or a revolving credit facility flexes with the practice's day-to-day needs: drawn and repaid repeatedly, it suits the general timing wobble of routine trading rather than one large liability with a known date. The full comparison of overdrafts, revolving credit, short-term loans and asset finance, and how to size each, is on our working-capital and overdraft finance page. This page deliberately does not repeat that ground.

The simple routing rule: if you can name the bill and its due date, a purpose-matched tax loan is usually the cleaner tool. If the need is a fuzzy, recurring, day-to-day gap, an overdraft or revolving facility is the better fit. The two are complementary, and many practices hold a modest overdraft for the everyday wobble while drawing a discrete tax loan only when a large HMRC bill falls awkwardly.

Which facility for which liability

A practical mapping of the main liabilities to the facility that usually fits best.

Liability	Due date shape	Usual best-fit facility
Income tax payment on account	Fixed: 31 Jan and 31 Jul	Short tax loan, repaid over the following quarter
Corporation tax	Fixed: 9 months + 1 day after year end	Short tax loan (if reserve falls short)
Quarterly VAT (VAT-registered practices only)	Fixed: 1 month + 7 days after quarter end	VAT loan (see the VAT loan page)
NHS year-end clawback	Dateable once reconciliation is calculated	Short tax loan or overdraft, depending on predictability
Everyday, unpredictable timing gaps	Fuzzy, recurring	Overdraft or revolving facility (see working-capital page)

The pattern across the table is consistent: a bill with a known amount and a known date is best matched to a self-liquidating tax or VAT loan, while a diffuse recurring gap is best met by a flexible facility. Getting the match right keeps the cost down and stops one need being funded with the wrong tool.

The tax on trade-purpose borrowing, in brief

The interest on a facility taken out wholly and exclusively to fund a tax or VAT bill is a deductible cost of the trade. For an unincorporated practice it is a deductible trading expense under the rules at HMRC's Business Income Manual (BIM45650 and following); for a dental company it is a loan-relationship debit deductible under CTA 2009 Part 5. Principal repayments are never deductible, they reduce a balance-sheet liability with no tax effect.

One asymmetry is worth holding onto, because it drives the decision. HMRC late-payment interest and penalties on a bill paid late are not deductible. So the true cost of letting a bill run late is higher than the headline penalty rate suggests, while the interest on a commercial loan taken to pay on time carries a tax offset. Borrowing to pay on time can therefore cost less in real terms than paying late, even before the reputational and compliance value of staying current with HMRC. The detailed penalty arithmetic for VAT specifically is worked through on the VAT loan page; the same principle applies across income tax and corporation tax.

Timing: match the facility to the bill, not to a loss

The single discipline that separates a healthy use of a tax loan from a damaging one is to match the borrowing to a bill you can see, funded by income that is genuinely coming. A tax loan bridges the space between a dateable liability and recovering trading income. It is not a way to fund a practice that is not making enough profit to meet its tax at all.

Worked example (illustrative): a January payment on account

The figures below are illustrative and not a quote. Consider a self-employed practice principal facing a £38,000 income tax bill on 31 January, the balancing payment for the prior year plus the first payment on account for the next. January is a quiet trading month after the Christmas break, and cash is tight because a chunk of the autumn surplus went on a new intra-oral scanner.

• The gap. The £38,000 falls due while January income is temporarily low. The practice is comfortably profitable over the year, but the cash is not in the account this month.
• The bridge. A short tax loan of £38,000 pays HMRC on time. At an illustrative 9% per annum over a three-month term, the interest is roughly £38,000 x 9% x 3/12 = £855, and that interest is deductible as a trading expense.
• The repayment. As February and March bookings recover, the loan is repaid across the following quarter and clears before the 31 July payment on account. The facility has done exactly its job: bridging timing, not funding a loss.

Contrast the wrong use. If the same practice reached 31 January unable to pay because the year had genuinely not produced enough profit, a tax loan would only defer the problem to July, when a fresh payment on account lands on top of the unpaid balance. Borrowing rolled forward each deadline, never clearing, is the signature of a profitability problem that finance cannot solve. The tell is a facility that never returns to zero. The fix in that case sits on the profit side, the cost base or fee income, not in more borrowing.

Where an accountant and a broker fit

For funding tax bills, the accountant comes first. Deciding whether a bill is a timing gap or a profit gap, sizing the liability accurately, confirming the reserve and checking the interest is deductible are all accounting judgements, and in most cases the better outcome is to reserve for tax so that borrowing is rarely needed at all. Our free practice health check is the natural starting point for that. Only once it is clear that a short-term facility is genuinely the right tool does a finance broker help source it, matched to the bill and the practice's cash cycle.

This decision often sits alongside longer-term borrowing questions. A practice carrying legacy acquisition debt may find that reviewing that facility, rather than adding a new short-term one, is the better move: our guide to refinancing a practice loan covers when a wider restructure makes sense. And if you are still at the buying stage, planning working capital into the deal from the outset is covered in our pillar guide to how to buy a dental practice.

This guide covers business-purpose commercial finance for a dental business only. It is not advice on personal or residential lending, which is separately regulated. Use the enquiry form below to tell us your segment (Associate dentist, Practice owner, or Multi-practice group) and whether you want the accounting review, the finance enquiry, or both. The mandatory data-sharing consent on that form lets us route your details to the right specialist.