Cash Basis or Accruals for a Stock Business? What Online Sellers Should Choose

When you set up as a sole trader selling online, HMRC's cash basis applies by default. For a freelancer or service provider this is usually fine. For a seller who buys stock to resell, it is almost always the wrong fit, and understanding why is one of the most practically useful things you can do for your bookkeeping.

The short answer

Cash basis is the default for unincorporated businesses; accruals must be actively elected. For a stock-based ecommerce seller, accruals accounting with proper inventory tracking generally gives better decision data and smoother taxable profits. Choosing the basis is an active decision, not a default to accept blindly. Source: HMRC cash basis guidance.

What the two bases actually mean

The distinction is about when income and costs are recognised, not how much you owe in total over a lifetime of trading.

• Cash basis: income is recognised when money arrives in your account; costs are recognised when money leaves. Simple to record, but the timing of cash movements drives what your accounts show.
• Accruals basis: income is recognised when it is earned (when you sell the goods) and costs are recognised when they are incurred (when you consume or sell the stock). Stock you have not yet sold sits on a closing-stock balance, not in your costs.

For a seller who never holds inventory overnight, the two bases produce nearly identical results. For a seller who buys a pallet of stock, holds it for weeks or months, and sells it in batches, the difference can be dramatic.

Why it matters for a stock business

Under accruals, cost of goods sold (COGS) is matched to the sales it relates to. Goods you have bought but not yet sold sit as a closing-stock asset, valued at the lower of cost and net realisable value, per HMRC BIM33115. Your taxable profit therefore reflects your trading performance in the period.

Under cash basis, every pound you spend on stock is a cost in the period you pay for it, regardless of whether any of that stock has sold. This drags forward costs into periods where no matching revenue exists, and then inflates apparent profit in later periods when the goods sell but no purchase cost appears.

What cash basis distorts for a seller: a worked example

Suppose you spend £8,000 on a wholesale stock order in March and sell £3,000 worth of it by 5 April (the tax year end), with the remaining £5,000 of stock sitting in your storage.

Cash basis result: your accounts show an £8,000 cost in the year, matched against only £3,000 of sales from that stock. The remaining £5,000 of goods you own appear nowhere as an asset. Your profit (on this batch alone) looks £5,000 worse than your actual trading performance.

Accruals result: your accounts show £3,000 of COGS (matched to the sales that occurred) and a £5,000 closing-stock asset. The profit on this batch reflects what you actually sold, and the unsold stock carries forward to next year as a cost that will reduce profit when those goods eventually sell.

Scale this across a business that regularly buys and holds, and the distortion compounds. In a growth phase, cash basis makes you look less profitable than you are during stock-building periods, and more profitable during periods when you run stock down without buying more.

The MTD for Income Tax context

Making Tax Digital for Income Tax requires sole-trader sellers with qualifying income above £50,000 to keep digital records and submit quarterly updates from 6 April 2026. The threshold drops to £30,000 from 6 April 2027 and to £20,000 from 6 April 2028. Source: HMRC MTD-IT eligibility guidance.

MTD does not mandate accruals accounting. A seller on cash basis can comply with MTD requirements. What MTD does is raise the cost of sloppy bookkeeping: quarterly updates expose year-round inconsistencies rather than letting them surface only at January. If your bookkeeping basis is producing a distorted profit picture, quarterly reporting makes that visible (and potentially problematic) four times a year instead of once.

For a full walkthrough of how MTD quarterly updates work and what records you need to keep, see our MTD ITSA guide for online sellers. For the generic mechanics of MTD ITSA (software, submission process, basis-period reform), the Holloway Davies MTD guide covers those in full.

Switching from cash basis to accruals

Switching is an active election, made to HMRC, and it is not something that happens automatically as you grow. The natural trigger is a year where your stock position is large enough that the distortion is material, or where you want reliable margin data for buying decisions.

The mechanics of switching involve transitional adjustments: income or costs that straddle the changeover must be treated carefully to avoid being double-counted (under both bases) or missed (under neither). This is not something to improvise. A clean year-end is the right moment to make the switch, and planning the transition with a bookkeeper or accountant before the new tax year starts avoids unwinding errors later.

Our settlement and payout reconciliation service is designed to support exactly this kind of structured bookkeeping clean-up, including basis-switch transitions for growing seller businesses.

When cash basis can still fit

Cash basis is not wrong for every seller. If you hold minimal stock (you are essentially a dropshipper with no stock in hand, or you sell digital products, or your physical stock position is small and turns quickly), the distortion is minor and cash basis's simplicity may be the right trade-off.

The typical profile where cash basis holds up:

• Very low stock value at any given time (turnover is rapid, stock is never a material balance)
• Side-hustle scale where total receipts are modest and bookkeeping overhead is a real constraint
• Service-heavy hybrid businesses where the trading activity is mostly labour or digital delivery

For Amazon, eBay, Etsy or Shopify sellers who regularly carry stock worth more than a few hundred pounds, the case for cash basis rests mainly on its lower bookkeeping overhead in-year, and that advantage shrinks once you have a proper inventory system in place. See the Amazon sellers hub and marketplace sellers hub for how we approach bookkeeping for different seller profiles.

Common failure modes

Two patterns come up repeatedly with growing sellers:

Drifting on cash basis while scaling stock. A seller starts out with £500 of stock, cash basis works fine, and the basis never gets revisited as the business grows. By the time stock is £20,000 or more, the cash-basis profit picture is significantly distorted. The tax position may be correct (over a lifetime of trading, the costs eventually flow through either way), but the management information is unreliable, and the year-end taxable-profit swings make planning difficult.

Switching without transitional adjustments. Moving to accruals mid-trade without identifying the opening stock value, outstanding creditors and debtors at the switchover date creates a bookkeeping gap. Costs already deducted on cash basis must not be deducted again under accruals, and sales already recognised under one basis must not recur under the other. The transitional year is the one to get right.

Both of these are preventable with a deliberate decision made at the right moment rather than a drift. If you are unsure which basis applies to your current accounts or whether a switch makes sense, our bookkeeping and reconciliation service can review your position.