Refinancing a dental practice loan can be one of the more sensible financial moves an owner makes: lower the monthly repayment, secure a better rate, consolidate scattered facilities, or release equity to reinvest. But it carries a tax dimension that owners regularly overlook, and the central principle is one worth committing to memory: the deductibility of your interest follows what the borrowed money is used for, not who lends it. Refinance business debt that stays in the trade and your interest remains deductible; draw out cash for personal use and you create a slice of interest that no longer qualifies.
This guide sets out the tax of refinancing and restructuring practice debt. We explain why swapping one business loan for another preserves the relief, the trap of releasing cash for personal spending, the treatment of early-repayment charges and arrangement fees, and how the mechanics differ between a sole trader and a company. The aim is to let you refinance for the right reasons while keeping every pound of interest relief you are entitled to.
Why practices refinance
There are several legitimate reasons to refinance. The most common is to improve cash flow by extending the term and lowering the monthly repayment. Others include securing a better rate, consolidating several facilities into a single, simpler loan, releasing equity to fund a refit or expansion, or restructuring the debt after a change such as bringing in a partner or buying out a departing one. Each can be sound, but each also has a cost: early-repayment charges on the old debt, arrangement fees on the new, and possibly more total interest if the term lengthens. Refinancing earns its place when the benefit clearly exceeds those costs, which is a calculation to run before committing, not after.
The tax rule: purpose follows the use of the money
The governing rule is the purpose test, and it looks at the use of the borrowed funds. Interest on borrowing used wholly and exclusively for the trade is deductible; interest on borrowing used for a personal or non-trade purpose is not. Crucially, the test does not care which bank provides the money or what the loan is secured against. It traces the borrowed cash to its actual destination. This single principle explains every refinancing outcome in this guide: keep the money in the business and the relief survives; take it out for yourself and part of the relief falls away. Tracing the money to its use is the whole of the analysis.
Tracing the borrowed money to its use
Because the purpose test turns on the use of the funds, it is worth understanding how that use is traced in practice, since a refinancing can mix several purposes. Where borrowing is used partly for the trade and partly for a personal purpose, the interest is apportioned between the two, with relief on the trade portion and none on the personal portion. The tracing follows the money: if a refinanced loan replaces an existing business loan pound for pound, the whole of it is for the trade and fully deductible; if it replaces the business loan and releases an extra slice taken personally, only the business slice qualifies. Keeping the borrowing cleanly attributable, so it is obvious which part funded the trade and which did not, makes the apportionment straightforward and defensible. Mixing trade and personal borrowing in a single muddled facility, by contrast, invites argument and can put even the legitimate trade relief at risk. The cleaner the link between the borrowed money and its business use, the cleaner the relief.
Refinancing business debt keeps the interest deductible
The good news for ordinary refinancing is that replacing one business loan with another, for the same trading purpose, keeps the interest deductible. If you refinance the loan you took to buy the practice with a cheaper or longer one, the new interest is just as deductible as the old, because the borrowed money is still funding the trade you bought. The change of lender, rate or term does not break the relief. This is why a practice can shop around for better borrowing terms without fear of losing its interest deductions, as long as the refinancing genuinely replaces business debt and the funds remain in the business. Our guide to financing a practice acquisition covers the original borrowing that refinancing typically replaces.
The trap: releasing cash for personal use
Here is where owners slip. If you refinance and draw out cash for personal use, a holiday home, school fees, or simply to live on, the interest on the portion used personally is generally not deductible, because that part of the borrowing has left the trade. The interest on the part that stays in the business remains deductible. So a refinancing that releases personal cash splits your interest into a deductible slice and a non-deductible slice, in proportion to how the money is used. This is easy to overlook, because the loan looks like a single business facility, but the tax follows the money, and money that ends up in your personal pocket takes its interest relief with it. If you are going to release cash personally, do it knowing the interest on that slice will not be deductible, and weigh that cost in the decision.
Early-repayment charges and arrangement fees
Refinancing triggers costs, and the good news is that most are deductible where the borrowing is for the trade. Early-repayment charges on the business debt you are replacing are generally deductible, as are the arrangement fees and incidental costs of the new finance, for a company under the loan-relationship rules and for an unincorporated business under the trading-expense rules. These costs can be substantial on a refinancing, so claiming them correctly is worth real money. As always, the borrowing must be for the trade for the costs to qualify, and where a refinancing is part business and part personal, the costs may need apportioning. Keep clear documentation of every charge and fee so your accountant can claim what is allowable.
Refinancing versus simply repaying faster
Before refinancing, it is worth asking whether the goal might be met more simply. If the aim is to reduce the total interest cost, overpaying an existing loan, where the terms allow it without penalty, reduces the balance and the interest without the cost and disruption of a new facility. If the aim is purely better cash flow in a temporary squeeze, a short-term working-capital facility alongside the existing loan may serve better than a full refinancing. Refinancing is the right tool when you genuinely need a different rate, a different term, a consolidated structure, or to release equity for the trade, but it carries its own costs, the early-repayment charges and arrangement fees, that a simpler approach avoids. Weighing refinancing against the simpler alternatives, overpaying, a separate short-term facility, or just holding course, ensures you take on the cost and effort of a new facility only when it genuinely delivers more than the easier options. Sometimes the best refinancing is the one you decide not to do, having found a simpler route to the same end.
Refinancing to release equity, and the tax line
Releasing equity by refinancing is possible and sometimes wise, but its tax efficiency depends entirely on where the released cash goes. If you release equity and reinvest it in the trade, new equipment, a surgery refit, working capital, an acquisition, the interest on the released amount stays deductible, because it remains business borrowing. If you release equity and take it out personally, the interest on that portion is not deductible. So the same equity release can be tax-efficient or not, depending on its destination. A release reinvested in the business is a deductible expansion of trade borrowing; a release taken personally is a non-deductible withdrawal dressed as a loan. Plan the destination of any released equity with the tax in mind, because it determines whether the interest works for you.
Restructuring debt after a change in the practice
Refinancing is often prompted not by a hunt for a better rate but by a change in the practice itself, and these situations carry their own tax considerations. Bringing in a partner may mean restructuring the debt so it sits appropriately across the partners, with each partner's borrowing to buy into the practice carrying its own deductibility analysis. Buying out a departing partner usually requires new borrowing, and whether the interest on it is deductible depends on what the borrowing funds: borrowing to acquire the departing partner's share of the trade can attract relief, while borrowing structured around personal interests may not. Incorporating the practice changes the structure entirely, moving the debt from the trading rules to the loan-relationship rules and interacting with goodwill and incorporation relief. Each of these is a moment where the debt is restructured for a real business reason, and each needs the interest position checked against the purpose test, because the change in circumstances can quietly alter what is deductible. Our guide to acquisition financing covers the borrowing that a buy-in or buy-out resembles.
The distinction between revenue and capital costs
Running through all of this is the revenue-versus-capital distinction, which decides what is deductible. Revenue costs, the interest, the early-repayment charges, the arrangement and incidental finance fees, are generally deductible where the borrowing is for the trade, because they are costs of obtaining and servicing business finance. Capital, principally the repayment of the loan principal itself, is never deductible, because it is the return of borrowed money rather than a cost of the business. Getting this line right is the heart of refinancing tax: a refinancing generates a cluster of revenue costs that are deductible and leaves the underlying capital, the principal, outside relief as always. An owner who understands that the cost of the finance is deductible while the finance itself is not will read every refinancing correctly, knowing to claim the charges and fees while never expecting relief on the capital being moved from one loan to another.
Consolidating multiple facilities
Many practices accumulate several facilities over time: an acquisition loan, equipment finance, perhaps a working-capital line. Consolidating these into a single loan can simplify administration and sometimes improve the rate or the cash flow. Where the consolidated borrowing replaces business debt and stays in the trade, the interest remains deductible. The points to weigh are the early-repayment charges on the facilities being replaced, the arrangement cost of the new consolidated loan, and whether a longer consolidated term increases the total interest paid over its life. Done for genuine business reasons with the money staying in the trade, consolidation keeps the relief and eases management, but the headline simplicity should not obscure the total-cost comparison. Our guide to equipment finance and its tax implications covers the asset-finance facilities that consolidation often sweeps up.
Documentation and evidencing the purpose
Because the deductibility of refinancing interest rests on the purpose of the borrowing, good documentation is what protects the relief if it is ever questioned. Keep clear records showing what each tranche of borrowing funded: the loan agreement, the use of the proceeds, and the link between the borrowed money and the business purpose. Where a refinancing replaces existing business debt, evidence the repayment of the old loan from the new one. Where any part is taken personally, record it honestly so the apportionment is clear and the legitimate business interest is not put at risk by association. This is not about creating bureaucracy; it is about being able to demonstrate, simply and credibly, that the borrowing was for the trade. A practice that can show a clean paper trail from loan to business use has nothing to fear from scrutiny, while one that has muddled trade and personal borrowing without records can struggle to defend even the relief it is genuinely entitled to. Your accountant will want these records anyway to claim the relief correctly, so keeping them is simply part of doing the refinancing properly.
Company versus sole trader treatment
The underlying principle, interest deductible where the borrowing is for the trade, is the same for both structures, but the mechanism differs. A company deducts its finance costs under the loan-relationship rules, and an unincorporated practice deducts interest under the trading-expense rules. For most refinancing the outcome is similar. A company has one extra piece of context, the Corporate Interest Restriction, which limits interest deductions only where a group's net interest expense exceeds £2 million a year, a level a normal single-practice dental company never approaches. So in practice a typical dental company gets full relief on its trade-related refinancing interest, and the restriction is a point to be aware of in principle rather than a real constraint. Whichever structure you use, the tax follows the use of the money in the same way.
A worked example
Take a practice refinancing a £400,000 business loan.
- Like-for-like refinancing. The full £400,000 replaces the existing business loan and stays in the trade. The interest on the whole new loan remains deductible, and the early-repayment charge on the old loan plus the new arrangement fees are also deductible.
- Refinancing with a personal release. Suppose the owner refinances at £450,000, using £400,000 to repay the business loan and drawing £50,000 out personally. The interest on the £400,000 business portion stays deductible; the interest on the £50,000 personal slice is not. The owner has created a permanent non-deductible portion of interest for the life of the loan.
- Refinancing with a reinvestment. If instead that extra £50,000 is spent on a surgery refit, the interest on the whole £450,000 is deductible, because all the money stays in the trade.
Same headline refinancing, three different tax outcomes, all decided by where the money goes. This is the purpose test in action.
Timing and the year-end
Refinancing has timing effects worth coordinating with your year-end. The early-repayment charges and arrangement fees fall in a particular accounting period, and a large deductible cost can be more or less valuable depending on the profit it lands against. The change in interest cost also shifts your ongoing profit and therefore your tax and any payments on account. None of this should drive the decision, but it is worth running the refinancing past your accountant so the deductible costs land sensibly and your tax payments are adjusted for the new interest profile. A refinancing planned with the year-end in view is cleaner than one that surprises the accounts after the fact.
The interest-rate environment and when to act
Beyond the tax, the commercial timing of a refinancing matters, and the two should be weighed together. Refinancing to secure a lower rate is most attractive when rates have fallen since the original borrowing, or when a practice's improved profitability and track record let it qualify for better terms than it could at the outset. Refinancing to extend the term and ease cash flow can be sensible when repayments are straining the practice, though it adds total interest over the longer life of the loan. The point is that a refinancing decision combines a commercial judgement, is the new deal genuinely better after all costs, with a tax judgement, does it preserve the interest relief and claim the deductible charges. A refinancing that looks good commercially but quietly creates a non-deductible personal slice, or one that preserves the relief but costs more than it saves, is only half right. Getting both halves right, with advice, is what makes a refinancing genuinely worthwhile rather than merely active.
When refinancing is and is not worth it
Refinancing is worth doing when the benefit, better cash flow, a lower rate, a simpler structure, or equity reinvested productively in the trade, clearly exceeds the costs of early-repayment charges, new fees and any extra total interest, and when the interest relief is preserved by keeping the money in the business. It is less attractive when it merely extends the term to release personal cash, because that both adds total interest and creates a non-deductible interest slice. The honest test is whether the refinancing leaves the business stronger, not just the owner's short-term cash position. Run that test with a specialist dental accountant, who can confirm the interest stays deductible, flag any non-deductible personal slice before you create it, and make sure the fees and charges are claimed in full. Our companion guides to strategic financial planning and to working capital and overdraft options sit alongside this one, because refinancing is rarely a standalone decision; it is part of how a practice manages its whole financing position. If a sale is eventually in view, our guide to the tax of a practice sale shows how the debt structure feeds the exit.