2. April 2026
Shopify Accounting Mistakes UK Sellers Make (And How to Fix Them)
The Shopify Accounting Mistakes UK Sellers Make (That Most Accountants Don't Even Know to Look For)
If you run a Shopify store and you have a general accountant — someone who also handles local tradespeople, small limited companies, and the occasional landlord's tax return — there is a reasonable chance your accounts contain errors you don't know about. This is not a criticism of generalist accountants. The problem is structural: Shopify's revenue model creates accounting complexities that are simply not part of standard bookkeeping training. The net payout that lands in your bank account looks like income. A generalist accountant treats it as income. It is not income — and everything that flows from that starting error cascades into your VAT calculations, your profit figures, and your understanding of your own business. Below are seven of the most common Shopify accounting mistakes we see when a new client comes to Taxity — along with why each one matters and what the correct approach looks like.
Mistake 1: Recording the Shopify Payout as Your Revenue
This is the foundational error — and it is almost universal among Shopify sellers who have not worked with a specialist. When Shopify pays you, it sends a net figure. Before that payout is calculated, Shopify has already deducted transaction fees, processing fees (if you use Shopify Payments), settled refunds from that period, shipping label costs if purchased through Shopify, and any reserve adjustments or dispute outcomes. The figure that arrives in your bank account can therefore look very different from your actual gross sales — particularly if you have a high refund rate or a busy promotional period. Why does this matter? Because your revenue for accounting and tax purposes is your gross sales — the amount your customers paid before Shopify took anything out. If your accounts show the net payout as income, you are understating revenue. You are also losing your platform fees from your expense records (because they were deducted before the deposit, they never appear in your bank account separately — so a bank-feed-only approach misses them entirely). The correct approach is to reconcile your actual Shopify sales data against your payout reports — not to use bank deposits as a proxy for income.
Mistake 2: Calculating COGS Incorrectly
Cost of Goods Sold (COGS) is the direct cost of the products you sold during a given period — the actual cost of the goods that left your inventory and reached a customer. It is not the same as your total stock purchases, and it is not the same as your total spending on products. The correct formula is: COGS = Opening Inventory Value + Purchases in the Period − Closing Inventory Value The timing of when you record COGS matters enormously. COGS should be recognised at the point of sale — when you sell a product, you recognise the cost of that specific product as an expense. If you buy £5,000 of stock in January and sell half of it in March, your January COGS is £0 on that stock (it is an asset — inventory — until it is sold), and your March COGS is £2,500. Many Shopify sellers — and some accountants — record all stock purchases as an expense when they are purchased. This is incorrect under UK GAAP and overstates your costs in the purchase period while understating them in future periods. It also makes your margin analysis meaningless. A related error is including indirect costs (paid advertising, packaging, software subscriptions) within COGS. These are operating expenses, not cost of goods sold. Mixing them inflates COGS and artificially depresses your gross margin.
Mistake 3: Monitoring the Wrong Revenue Figure for the VAT Threshold
The VAT registration threshold in the UK (£90,000 for 2025/26) is based on your taxable turnover — your gross sales, including VAT where applicable, before any platform fees or deductions are applied. If you have been tracking your Shopify payouts as revenue, you have been monitoring a net figure. Depending on your refund rate and fee structure, your actual gross turnover could be 5–15% higher than your net deposits. That gap can be enough to push you over the threshold without either you or your accountant realising it. The consequences are significant. HMRC can backdate a VAT registration to the date you should have registered — meaning you would owe VAT on all taxable sales from that date, whether or not you collected it from your customers. In a worst case, you eat the VAT out of your margin on every sale you made while unregistered. Proper Shopify accounting monitors your rolling 12-month gross turnover — pulled from your actual sales data, not from bank deposits — and flags the threshold approach well in advance.
Mistake 4: Treating Refunds as an Afterthought
Refunds are common in ecommerce — particularly on Shopify stores with generous return policies. From an accounting perspective, refunds need to be handled correctly at every level: revenue, VAT, and inventory. The typical error is not recording refunds at all in the accounting system — instead, they simply reduce the net payout figure, and since that deposit is what gets recorded as income, the refund is invisible in the accounts. This creates two specific problems: First, your revenue is overstated in the period the sale was made and understated in the period the refund was processed — the matching principle is broken. Second, if you are VAT registered, a refund represents output VAT that you over-collected and must credit back. If refunds are not being recorded individually, your VAT returns may be overstating your output VAT liability — meaning you are paying HMRC more VAT than you owe. Additionally, when a refund results in a returned item, your inventory needs to be updated. A returned item that is resalable goes back into stock at its original cost; an item that cannot be resold should be written off. Neither of these adjustments happens automatically — they require active inventory management.
Mistake 5: Not Separating Shopify Transaction Fees by Type
Shopify charges fees in several different ways, and recording them all as a single 'Shopify fees' expense is a missed opportunity both for accuracy and for tax purposes. Here is what the fees actually consist of, depending on your setup: • Shopify subscription fee — your monthly plan cost (Basic, Shopify, Advanced, or Plus). This is a straightforward software subscription expense. • Shopify Payments processing fee — charged per transaction on the value of the sale plus any applicable taxes. This is a payment processing cost. • Third-party transaction fee — if you use a payment gateway other than Shopify Payments, Shopify charges an additional fee (0.5%–2% depending on your plan) on every transaction. • Third-party payment processor fee — the fee charged by Stripe, PayPal, or whoever processes the payment, separate from Shopify's fee. • App subscription costs — any paid Shopify apps (email marketing, review platforms, subscription tools) are separate software expenses. Proper Shopify accounting separates these into appropriate expense categories. The distinction matters for management reporting (understanding where your costs actually sit) and occasionally for VAT recovery (input VAT on certain business costs).
Mistake 6: Ignoring Shopify Markets and EU VAT Obligations
Shopify's international selling features — particularly Shopify Markets — make it straightforward to sell into EU countries. What Shopify does not do is tell you what your VAT obligations are in those countries. Since Brexit, UK sellers no longer benefit from the EU's distance selling rules in the same way. The relevant regimes for UK Shopify sellers with EU customers are: OSS (One Stop Shop): If your total taxable B2C sales into EU countries exceed €10,000 per year, you are required to account for VAT in each destination country. Rather than registering separately in each EU member state, you can use the EU's OSS scheme to file a single quarterly return covering all EU sales. The return must correctly apply the VAT rate of each country where your customers are based. IOSS (Import One Stop Shop): For goods with a value of up to €150 imported into the EU from outside (i.e., from the UK), IOSS allows sellers to collect VAT at the point of sale and remit it through a single EU return, rather than having the customer pay import VAT on delivery. Many UK Shopify sellers with growing EU sales are simply not aware of these obligations — and neither are most generalist accountants. The penalties for non-compliance can include back-taxes and interest in the relevant EU member states. If your Shopify store sells into Europe, this is an area where specialist advice matters. [Related: our ecommerce accountant page covers EU VAT compliance in more detail → Ecommerce Accountant]
Mistake 7: Waiting Until Year-End to Find Out Your Real Numbers
Perhaps the most expensive mistake on this list — not because of the direct financial error it creates, but because of the decisions it prevents you from making. Many Shopify sellers work with an accountant who files their annual accounts nine months after their year-end. By the time those accounts arrive, the figures are almost a year old. Your most recent Christmas trading period is not in them. The product line you discontinued in March is not in them. The platform fee increase that squeezed your margins in Q2 is not in them. You cannot make good business decisions — about pricing, about marketing spend, about whether to launch a new product line, about whether to hire — based on data that is this old. Once your Shopify store crosses approximately £50,000 in annual gross sales, you need monthly management accounts. A clear P&L every month, by platform if you sell on more than one, showing you: • Gross revenue (actual gross sales, not net payouts) • Platform fees and processing costs • COGS (correctly calculated) • Gross profit and gross margin • Operating costs (ads, apps, fulfilment, salaries) • Net profit With Xero connected to your Shopify store, this is not complicated or expensive. It is simply what good Shopify accounting looks like.
What to Do if You Recognise These in Your Own Accounts
If you have read through this list and recognised your own situation in one or more of these errors — you are not alone. These are the most common issues we see when a new Shopify client comes to Taxity, and in almost every case, the seller's previous accountant was trying their best with tools and training that were not designed for ecommerce. The starting point is getting your Shopify store properly connected to Xero — which means reconciling actual sales data, not just bank feeds — and reviewing your most recent period's figures against what your bank statements show. If you would like to understand exactly where your current Shopify accounting stands, book a free 30-minute discovery call with Travis at Taxity. We will look at your current setup, identify the specific issues, and give you an honest assessment — whether or not you become a client. [Book a free call → Contact] [Find out more about our Shopify accountant service → Ecommerce Accountant]
