US Personal Tax Services: UK Cash Basis vs US Reporting

An American consultant trading as a UK sole trader will hold two different profit figures for the same work. UK accounts are prepared on the cash basis, now the default, for a year ending 5 April. The US Schedule C reports a calendar year in dollars under its own method rules. Reconciling the two, not choosing between them, is the task.

This is one of the most commonly mishandled areas in US personal tax services for British-based Americans. The error is rarely dramatic. It is usually a single number lifted from box 47 of a Self Assessment return and dropped onto a Schedule C, with no adjustment for the four-month calendar shift, no currency discipline, and no thought given to whether the capital spending deducted in the UK belongs in the US year at all. At Jungle Tax we see it most often when a client comes to us for a compliance catch-up and asks us to reconstruct several years at once.

Why does the same trade show a different profit in each country?

There are four independent sources of divergence, and they compound. Treating them as one problem is why reconciliations fail.

• Method. The UK measures profit on money received and money paid. The US asks you to adopt a method that clearly reflects income and to apply it consistently, and for many professional service traders that is also a cash method, but the two are not automatically identical in operation.
• Period. The UK year ends 5 April. The US year ends 31 December. Roughly a third of every UK year sits in the following US year.
• Currency. UK accounts are in sterling throughout. The US return is in dollars, translated item by item, and the translation itself moves the answer.
• Capital. The cash basis deducts most equipment when paid. The US generally capitalises assets with a useful life beyond the year and recovers them over time, subject to available expensing provisions.

A consultant with £180,000 of fee income and a March equipment purchase can easily see a five-figure difference in reported profit between the two returns for what feels like the same twelve months. That difference is correct. It is not an error to be smoothed away; it is a reconciliation to be documented.

What the UK cash basis includes and excludes

From the 2024/25 tax year the cash basis became the default for UK sole traders and partnerships made up of individuals. This was a reversal of the previous position, under which the cash basis was an opt-in regime with a turnover ceiling. The reform also removed the turnover thresholds for entering and leaving the basis, removed the cap on interest deductions, and aligned loss relief with the accruals basis so that cash basis losses can be relieved sideways against general income or carried back. HMRC's policy paper on expanding the income tax cash basis sets out the changes.

In practice, for a consultancy trade, the cash basis means:

• Included: fees actually banked in the year, expenses actually paid in the year, and most plant, equipment and technology deducted in full at the point of payment.
• Excluded: debtors and creditors. An invoice raised on 20 March and settled on 12 April falls into the following UK year. A supplier bill dated February but paid in May does the same.
• Treated separately: cars. The cash basis does not permit a straightforward deduct-when-paid treatment for a car, and business motoring is commonly handled through the approved mileage rates.

The consequence for the US filer is that UK accounts contain no accruals data at all. There is no debtors schedule to work from, because the UK return never needed one. If a US position requires accrual information, it has to be rebuilt from the invoice ledger, not extracted from the accounts.

What the US Schedule C actually asks for

Schedule C requires an affirmative statement of accounting method. The IRS instructions for Schedule C confirm that a taxpayer may generally use the cash method, an accrual method, or another permitted method, provided the method clearly reflects income. Under a cash method you report all items of taxable income actually or constructively received and amounts actually paid for deductible expenses during the year. The instructions also flag that payments creating an asset with a life substantially beyond the year may need to be capitalised rather than deducted.

Two features matter disproportionately in a cross-border reconstruction:

Consistency. The method you adopt is the method you are expected to keep. Where a change is required, it generally means a formal application on Form 3115 with a section 481(a) adjustment, calculated so that income and expense are neither duplicated nor omitted. A net negative adjustment is typically taken in the year of change; a net positive adjustment is typically spread. None of this is something to discover halfway through a three-year catch-up.

Constructive receipt. Cash-method US reporting is not simply "money in the bank account". Income is included when it is credited to your account, set apart for you, or otherwise made available to draw on. For a consultant paid through a platform, a factoring arrangement, or a client portal with a delayed withdrawal step, the US receipt date can precede the UK banking date. That is a genuine, and frequently missed, source of divergence.

UK cash basis versus US Schedule C: the practical comparison

Feature	UK sole trader, cash basis	US Schedule C
Status of the method	Default from 2024/25; accruals requires an election	Elected on the return; must clearly reflect income
Period measured	6 April to 5 April	1 January to 31 December
Currency	Sterling	US dollars, translated per item
Income recognition	Cash received	Received or constructively received
Debtors and creditors	Ignored entirely	Ignored under cash method; recognised under accrual
Equipment and technology	Generally deducted when paid	Generally capitalised; recovered by depreciation or expensing election
Cars	Approved mileage rates commonly used	Standard mileage rate or actual costs, with its own listed-property rules
Changing method	Election year by year on the return	Generally Form 3115 with a section 481(a) adjustment
Social security charge	Class 4 and Class 2 National Insurance	Self-employment tax, subject to treaty relief

How do you re-cut UK accounts to a US calendar year?

You cannot apportion a UK profit figure by nine-twelfths and call it a Schedule C. The income is not earned evenly, the expenses are not paid evenly, and a single large receipt in February will sit on the wrong side of any pro-rata line. The re-cut has to happen at transaction level.

The working method we use is:

• Assemble a continuous dated ledger across the whole period under review, not year by year. For a three-year catch-up that means a single dataset running from roughly 6 April three years before the first US year to 5 April after the last, so that both tails are covered.
• Tag every line with its US recognition date, which is the receipt or payment date for a cash-method filer, adjusted for constructive receipt where a platform or intermediary is involved.
• Cut at 31 December and confirm that every transaction in the period appears in exactly one US year. The control total is that the sum of the US-year slices equals the sum of the UK-year slices over the overlap window.
• Translate, then total. Translating after cutting, rather than before, keeps the audit trail intact.
• Reconcile back to the Self Assessment return for each UK year with an explicit bridging schedule. That schedule is the deliverable. It is what answers a future question from either revenue authority.

Currency translation in a re-cut

The IRS guidance on foreign currency and currency exchange rates states that where the dollar is your functional currency you translate items of income and expense at the rate prevailing when you receive, pay or accrue them, and that where more than one rate exists you use the one that most properly reflects income. For a stream of routine trading transactions a published yearly average is widely used and defensible. For large or unusual items, and for the capital additions discussed below, a transaction-date rate is usually the better answer. What matters is that the choice is deliberate, documented and applied the same way across every year of the catch-up.

Capital expenditure: the divergence that outlasts the year

This is the adjustment that persists. A workstation, camera kit, or specialist software licence bought in the UK year to 5 April 2025 may have been deducted in full in the UK accounts under the cash basis. On the US side, an item with a useful life substantially beyond the year is generally a capital item, recovered through depreciation or an available expensing provision, and your US basis in that asset carries forward.

Three practical consequences follow:

• A permanent schedule is required. Every asset needs an acquisition date, a sterling cost, a translated dollar cost and a US recovery position. Without it, year four of the trade has no defensible depreciation figure.
• Disposals diverge too. A cash-basis UK trader who sells equipment brings the proceeds in as a receipt. The US treatment depends on basis and prior recovery, which is a different computation with a different answer.
• The mismatch is a timing difference, not a windfall. Over the life of the asset the deduction is the same in both countries. It simply lands in different years, which is exactly what distorts the credit position discussed next.

Why does the foreign tax credit rarely line up?

Here is the sequence that causes the problem. A UK trading profit for the year to 5 April 2026 is reported on a Self Assessment return due by 31 January 2027. Tax on it is collected through payments on account in January 2026 and July 2026, and a balancing payment in January 2027. Those three payments fall into two different US calendar years, and neither of them is the year in which the underlying profit was mostly earned for US purposes.

A cash-method US taxpayer generally credits foreign tax in the year it is paid. The result is credits arriving in the wrong year relative to the income they relate to: one year shows foreign income with thin credits, the next shows credits with insufficient income to absorb them. Carryback and carryforward exist to relieve this, but only after the excess has crystallised, and only within the same credit category.

The Form 1116 alternative is to claim credits on an accrued basis, matching UK tax to the year of the income rather than the year of payment. It sounds like the obvious fix. It is not a light decision: the election has lasting consequences for how every subsequent year is computed, it requires reliable accrual data for a trade whose UK accounts contain none, and it interacts with the redetermination rules when a UK liability later changes. We model it before we recommend it, and we do not make it mid-catch-up simply because it produces a better number in one year.

What we ask for before touching the credit computation

• HMRC statements of account showing the actual date of every payment on account and balancing payment.
• The tax calculation (SA302 or equivalent) for each UK year, so the liability can be allocated to its source income.
• Evidence of any repayment or amendment, because a refunded payment is not creditable tax.
• The Class 4 and Class 2 National Insurance split, which is not income tax and is treated separately.

Self-employment tax and the social security agreement

A US citizen trading as a UK sole trader is within the scope of US self-employment tax by default. Where the US-UK social security agreement applies and the individual is contributing to UK National Insurance on that self-employment, a certificate of coverage obtained from HMRC evidences that the earnings belong to the UK system and are outside the US charge. The certificate is retained and referenced on the US return.

Two points are regularly misunderstood. First, this relieves the self-employment tax charge only; the profits remain fully within US income tax, subject to whatever exclusion or credit position applies. Second, the certificate has to exist for the years concerned. In a catch-up covering earlier years, obtaining the correct historic coverage evidence is a workstream in its own right, and it is one that cannot be reconstructed retrospectively from the accounts.

Rebuilding several years of Schedule C in a compliance catch-up

Most of the sole traders who come to us are not arguing about method. They have simply never filed the US side, or filed it thinly, and now need to put several years right at once. The Streamlined Filing Compliance Procedures are the usual route for a non-willful taxpayer resident outside the United States, and the foreign offshore track is built around the three most recent years for which the return due date has passed, six years of FBARs, and a signed non-willful certification. Our streamlined filing team runs these end to end.

A sole trade makes that submission materially heavier than a wages-and-pension catch-up, because three Schedule Cs means three independent re-cuts, three currency translations, a continuous asset register spanning all of them, and a credit computation that has to be internally consistent across the set. The sequence we follow is:

• Scope the period. Identify the three US years, then extend the data window four months either side so both UK tails are captured.
• Establish the method and fix it. Decide the US accounting method once, document why it clearly reflects income for this trade, and apply it identically to every year in the submission. Inconsistency across the three years is what draws questions.
• Build the ledger, then cut it. Transaction-level, dated, tagged, cut at each 31 December.
• Build the asset register. Every capital item since the trade began, not just within the streamlined years, because basis carries forward from before the window.
• Layer the credits. Map every HMRC payment to its US year on the chosen basis, and test the carryforward and carryback position across the set as a whole rather than year by year.
• Check the surrounding compliance. Foreign business and personal accounts, any UK pension or investment holdings, and the FBAR and Form 8938 positions that the trade itself often brings into scope. Our wider US-UK tax team handles those alongside the Schedule C work.
• Write the bridging narrative. A short, clear explanation of how the UK cash-basis accounts became these Schedule Cs, retained on file.

A note on what this work is, and is not

We prepare returns. Our job on an engagement like this is to establish what actually happened, report it accurately in both countries, and leave behind a reconciliation that stands up. We do not recommend adopting one basis over another because it produces a lower liability, and we are sceptical of anyone who does so before the underlying reconstruction is complete. Both regimes have consistency rules. A method chosen to flatter a single year usually costs more in the years that follow, and a method changed mid-catch-up undermines the submission it sits inside.

Where genuine structural questions arise, for example when a trade has outgrown sole trader status entirely, that is a separate conversation and a separate piece of work. You can read more across our cross-border guides.

Bringing it together

One trade, two sets of books, cut on two different calendars, measured in two currencies, with capital spending recognised at different speeds and tax credited on a different clock. None of that is a problem to be solved by picking a side. It is a reconciliation to be built once, carefully, and then maintained.

If you are an American consultant or founder trading as a UK sole trader with US returns outstanding, or with filed returns you are no longer confident in, we can review the position discreetly and tell you what the reconstruction actually involves before you commit to anything. Contact our cross-border team to arrange a confidential consultation with a senior US-UK specialist.