Why a Partner's Tax Bill Arrives in Lumps (and Why Borrowing Is Even a Question)

A self-employed partner or LLP member is taxed on their allocated profit share, not on their drawings. Drawings are simply cash advances against the share, so a partner who draws conservatively still pays tax on the full allocation. That single feature, more than any other, is what makes a partner's tax bill feel disconnected from the money in their personal account.

The bill then arrives in lumps. Income tax and Class 4 National Insurance on partnership profits are collected through two payments on account, due 31 January and 31 July (TMA 1970 s.59A), each broadly 50% of the prior year's self-assessment liability, with a balancing payment the following 31 January. The first January a partner is fully inside the payments-on-account regime can feel brutal: the balancing payment for the prior year plus the first payment on account for the current year can together approach 150% of a single year's tax in one demand.

For many partners that spike is currently amplified by the basis-period-reform transition charge. Firms with a year end other than 31 March or 5 April had transition profits to bring into charge, spread at 20% a year and still being collected through 2027/28 (see the basis period reform guide for law firms). When a partner's reserve falls short of one of these demands, or when lock-up has tied the firm's cash up in unbilled work and unpaid invoices, the question of borrowing to meet the bill arises.

This guide does three jobs. It explains how a tax loan or fee-funding facility works and where it fits the partner cash-flow calendar; it gives the cash-flow logic honestly; and it states the deductibility position carefully and correctly. If you are looking at the saving side of the same problem, our companion guide on reserving for payments on account covers how much to set aside in the first place.

What a Tax Loan or Fee-Funding Facility Actually Is

A tax loan (also called a fee-funding, tax-funding or professions-funding facility) is a short-term, usually unsecured loan equal to the tax due. The lender pays the amount to HMRC or to the partner, and the partner repays it over a fixed term (commonly several monthly instalments) with interest or an arrangement fee. These facilities are often arranged through brokers and insurers that specialise in funding professional-firm tax and practising costs, and they are sometimes provided by the firm to its partners as a managed scheme.

One distinction matters from the outset, because it drives the deductibility analysis later: a facility can be partner-arranged (the individual borrows in their own name to pay their own tax) or firm-arranged (the firm sets up or provides the funding for its partners). In both cases the underlying liability being funded is the partner's personal tax. The label on the facility does not change that, and neither, as we will see, does it change the tax treatment of the interest. We do not quote prices here; the cost varies by lender, term and the partner's circumstances.

It helps to be clear about what a tax loan is not. It is not a deferral of the tax itself: HMRC is paid in full and on time, and the partner's debt is to the lender, not to HMRC. It is not security against the firm's assets in the usual case (most facilities are unsecured against the partner). And it is not a discount: nothing about borrowing changes the income tax or Class 4 NIC computed on the profit allocation. The product simply rearranges the timing of the cash outflow, in exchange for a financing cost. Holding that plainly in mind keeps the later analysis honest, because the temptation with any borrowing is to talk about it as though it reduced the underlying obligation. It does not.

Where It Fits the Partner Cash-Flow Calendar

The natural home for a tax-funding facility is the 31 January and 31 July payment-on-account dates, and in particular the balancing-payment pile-up that lands each 31 January. A facility can convert that concentrated demand into a smoother monthly profile, which is useful when a partner's drawings are steady but their tax falls in two large hits a year.

It can also fund the transition-profit slice still feeding partners' bills to 2027/28. Under Finance Act 2022, the transition profits (the catch-up from the old basis-period date to 5 April 2024, net of any unused overlap relief) are spread at 20% a year across 2023/24, 2024/25, 2025/26 and 2026/27, with the balance treated as arising in 2027/28, unless the partner elects to accelerate. The transition charge is taxed as a standalone charge and falls within Class 4 NIC. Because it is calculated from a known starting point and spread over a fixed run of tax years, it is one of the most predictable demands a partner faces. That predictability is exactly why a facility used to bridge it should be a deliberate choice rather than a panic response.

The benefit of any tax loan is smoothing, not saving: it changes when the cash leaves your account, not how much tax you owe. For a partner whose drawings are paid in regular monthly amounts but whose tax falls in two large hits, that smoothing can be genuinely useful: it aligns the outflow with the income. But the alignment comes at a cost (the interest), and that cost is borne after tax because, as the next section explains, it is not deductible. So the right question is not "can I afford the monthly instalment" but "is the financing cost worth paying to move the timing, given I cannot offset it against my profits". For a one-off shortfall the answer is often yes; as a recurring crutch it is a sign the reserving and lock-up problem needs fixing at source.

The Deductibility Question, Answered Honestly

This is the section the marketing usually skips, and it is the most important point on the page. Interest on borrowing is allowable as a deduction only to the extent the borrowing is wholly and exclusively for the purposes of the trade (ITTOIA 2005 s.34). HMRC's guidance in BIM45690 puts it plainly: where a business is funded using borrowed money used for business purposes, the interest is allowable; the interest is not allowable if the funds are used for private purposes, including where the borrowing finances private spending because the proprietor has taken more out of the business than they have put in or earned in profits.

A partner's own income tax and Class 4 NIC is a personal liability and an application of profit, not an expense of running the firm. Paying the proprietor's tax is not a purpose of the trade. It follows that interest on a loan taken to pay a partner's personal tax is generally not an allowable trade deduction. Say it to yourself in those terms before you take a facility: the interest is a personal cost that you bear out of taxed income, with no offset against the firm's profits.

Contrast this with a genuine working-capital facility. Where the firm borrows to fund the trade itself (to carry work in progress, to cover a payroll run, to invest in the practice), the interest on that borrowing is a trade expense, because the purpose of the borrowing is the trade. That is a different transaction with a different answer. The error to avoid is assuming that because some firm borrowing is deductible, borrowing to pay a partner's tax must be too. It is not.

A related trap is the proprietor's drawings point in BIM45690. If a partner draws out more than they have put in or earned, and the firm then borrows to make good the resulting cash gap, HMRC can treat that borrowing as financing the partner's private withdrawals rather than the trade, and restrict the interest accordingly. So you cannot reliably convert non-deductible personal-tax borrowing into deductible firm borrowing by routing it through the firm's overdraft and increasing drawings to match. The substance, what the money actually funded, governs the deduction. Where a firm genuinely needs working capital and separately a partner needs to fund their tax, the clean approach is to keep the two facilities, and the paperwork that records their purpose, distinct from each other.

There is also no income-tax relief route that rescues the interest. Qualifying-loan interest relief under ITA 2007 (covered in the next section) is for borrowing to invest in the partnership's capital, not for paying tax. And the personal allowance, dividend nil rate and other reliefs do not touch financing costs on a personal tax bill. The honest bottom line is that the cost of a tax loan is a real, after-tax cost with no offset, which is exactly why it should be compared squarely against the alternatives rather than waved through as "just a business cost".

The Capital Buy-In Distinction (Do Not Confuse the Two)

There is a second, genuinely valuable relief that is easy to confuse with a tax loan, so we keep it in a separate box. Interest on a personal loan taken to fund a genuine capital contribution to (or buy-in to) the LLP can qualify for income-tax relief under ITA 2007 ss.398 to 412 (a qualifying loan to invest in a partnership), for as long as the member remains a partner and the capital stays in the firm.

That relief is real, and a newly promoted partner funding a capital contribution should make sure they claim it. But notice what it relieves: borrowing to put capital into the partnership. It has nothing to do with borrowing to pay a tax bill. The clean way to hold the two ideas is:

  • Borrowing to buy in (capital): interest can be relievable under ITA 2007 ss.398 to 412.
  • Borrowing to pay your tax (personal liability): interest is generally not relievable.

For the mechanics of how a buy-in sits in the books, see our guide on law firm partner capital accounts and their tax treatment. If you borrow for both purposes, keep the loans (and the documentation of what each one funded) entirely separate, because they are taxed differently.

Tax Loan vs HMRC Time to Pay

Before reaching for a commercial facility, weigh it against HMRC's own instalment route. A Time to Pay arrangement lets a taxpayer spread a self-assessment bill in instalments agreed with HMRC, which charges late-payment interest at a published rate. We do not quote a figure here because that rate moves; check the current rate at the date you apply. Time to Pay is essentially deferring the tax with HMRC rather than borrowing from a third party.

A commercial tax loan may be quicker to arrange, may cover a larger or earlier demand, and keeps your HMRC account clear, which some partners prefer. Against that, it is third-party borrowing with its own cost, and, as above, the interest is generally not deductible. Frame this as a comparison rather than a recommendation: line up the total cost of each route and the practical considerations, and choose on the facts. There is no single right answer.

Reducing Payments on Account Instead of Borrowing

If your tax liability for the year is genuinely lower than the prior year, the cheapest lever may not be borrowing at all but reducing your payments on account. A partner whose profit share is falling can claim to reduce both payments on account to reflect the expected lower liability.

The discipline is to reduce only to a figure you can defend. If you reduce too far and the year's liability turns out higher, HMRC charges interest on the shortfall back to the original due dates. So this is a lever to pull on evidence, not optimism, and it pairs naturally with the forecasting discipline described in the reserving guide. Used well, a defensible reduction can shrink the demand you would otherwise have to bridge.

The Lock-Up Trap That Drives the Borrowing

Here is the cruel structural point for law firms. You are taxed on your allocated profit share even where the firm's cash is locked up in unbilled work in progress and unpaid debtors. Work in progress is recognised as revenue under FRS 102 as the firm obtains the right to consideration, so it sits on the balance sheet and is taxed as it is recognised, not when it is billed and collected.

A profitable firm with heavy lock-up can therefore leave a partner owing tax on profit that has not yet turned into drawable cash. That is precisely the moment a tax loan looks attractive, and precisely the moment to remember that the loan is a bridge, not a cure. The durable fix is reducing lock-up: billing promptly, tightening credit control and shortening work-in-progress and debtor days. See our guides on reducing law firm lock-up and law firm cash flow management for the levers that stop the shortfall recurring.

Firm-Arranged Facilities and the Partnership Books

Where the firm arranges or provides the funding to partners, set the bookkeeping out cleanly so nobody mistakes the substance:

  • A loan from the firm to a partner is the partner's borrowing, recorded as a receivable from the partner (or against their current account), not as a firm expense.
  • Any interest the firm charges the partner is the firm's income, not a deduction.
  • The partner's tax remains the partner's personal liability throughout.

The temptation to resist is presenting a firm-level facility as a way to "make the interest deductible". It does not. The purpose of the borrowing is still the payment of a partner's personal tax, so the non-deductibility analysis above is unchanged. Where the firm itself borrows for genuine working capital, that is a separate matter covered alongside other options in our overview of solicitor practice finance options.

A Worked Example: Bridging a January Shortfall

Illustrative only, not advice; figures rounded and rates as at June 2026.

Scenario. A partner faces a 31 January demand of £48,000 (a £24,000 balancing payment for the prior year plus a £24,000 first payment on account for the current year). Their tax reserve holds £30,000. The £18,000 gap has arisen because a large matter billed late and the cash is still in debtors.

Action. The partner takes a tax loan of £18,000 to meet the demand in full on 31 January and repays it over the following months. The instalments smooth the cash, and the bill is paid on time, avoiding HMRC late-payment interest on the £18,000.

The deductibility point. The interest on the £18,000 facility relates to paying the partner's personal income tax and Class 4 NIC. It is therefore not an allowable trade deduction. The partner bears that interest as a personal cost out of taxed income. The loan has bought time and protected the partner from HMRC interest, but it has not reduced the tax and it has added a small after-tax cost. The lesson for next year is to reserve against the allocation and chase the late bill sooner, so the gap does not reopen.

Decision Frame and Checklist

When a tax-funding facility is on the table, work through this frame:

  1. Reserve first, borrow to bridge. A facility should bridge a genuine shortfall, not substitute for setting money aside against the profit allocation.
  2. Assume the interest is not deductible. Treat tax-loan interest on personal tax as a personal, after-tax cost (BIM45690; ITTOIA 2005 s.34).
  3. Compare the routes. Line up a commercial tax loan against HMRC Time to Pay and against a defensible reduction of payments on account; choose on total cost and the facts.
  4. Keep capital buy-in separate. Qualifying-loan interest relief under ITA 2007 ss.398 to 412 is for partnership capital, not for tax. Do not blur the two.
  5. Plan the transition slice. Treat the basis-period transition charge running to 2027/28 as a known, plannable demand.
  6. Attack lock-up. The durable fix is shortening work-in-progress and debtor days so profit becomes cash before the tax falls due.

If you are weighing how to fund a partner tax demand, our team works with law firm partners on the cash-flow, the reserving discipline and the honest deductibility position behind these facilities. Talk to us before you sign, not after.

This page sits alongside three Cluster E companions on funding the firm's obligations: the apprenticeship levy and solicitor apprenticeships, secondment of solicitors and its VAT and tax treatment, and financing PII premiums and the tax treatment of premium finance.

Specialist Note

The deductibility position in this guide is the load-bearing point, and it is the one most often mis-stated. Interest on borrowing to pay a partner's personal income tax and Class 4 NIC is, in the ordinary case, not an allowable trade deduction; interest on a qualifying loan to fund partnership capital can be. Your own position depends on what your borrowing actually funds and how the facility is documented. Speak to a legal-sector-specialist accountant who can map the facility to the right tax treatment and check it against your firm's books before you commit.