How to Read an eCommerce P&L: The Numbers That Matter

To read an eCommerce P&L, start with net sales (after VAT, discounts and refunds). Subtract cost of goods sold to get gross profit, then deduct shipping, payment fees and advertising to reach contribution margin. Finally, subtract overheads, interest and tax to reach net profit.

Your dashboard says sales are up, but your bank balance isn’t. That gap is where a profit and loss (P&L) statement earns its place. 

The situation for UK eCommerce sellers is more complicated than it first appears. VAT inflates your headline sales, returns subtly reduce revenue, advertising, courier costs and payment fees take much of what is left. A busy store is not always successful, and revenue does not equate to profit. 

In this guide, we break down how to read an eCommerce P&L line by line. You will understand which numbers matter most, including gross margin, contribution margin, and net profit, what “good” looks like, and the red flags to watch for before they hurt your cash flow.

The Key eCommerce P&L Numbers That Show What You Really Keep

eCommerce sales numbers may seem amazing, but how much money does your company really keep after all expenses are paid? You can discover it by looking at your eCommerce P&L statement. Determine your true profitability, spot wasteful spending, and make wiser business decisions by monitoring these crucial numbers.

1. Net Sales: Revenue from goods sold after VAT, discounts, refunds and returns. Keep separate records of each, so you can see the true revenue your company generates.

2. Cost of Goods Sold (COGS): The direct costs of the goods you sell, such as manufacturing or buying expenses, inbound freight, import duty and packaging. It excludes outbound shipping, which is usually a separate distribution cost. 

3. Gross Profit Margin: The portion of earnings that remains after subtracting the cost of goods sold. A bigger gross profit margin indicates that there is more money available to make a profit and pay operating costs. 

4. Advertising and Marketing Costs: The amount of money you spend on advertising platforms such as Google Ads, Meta Ads, and influencer campaigns. Check and compare all costs with the volume of  sales they are generating to see whether your marketing is providing the desired results.

5. Fulfilment and Shipping Costs: The costs of picking, warehousing and delivering orders. These expenses can quickly reduce profits, especially when customers expect free or low-cost delivery. 

6. Marketplace and Payment Fees: When using marketplaces like Amazon and eBay, you are likely to pay fees based on your sales figures. Both payment service providers (e.g. Stripe, PayPal, and Shopify Payments) charge fees for processing payments. By keeping track of both fee types, you can get a better sense of how much these fees cut into your profit margins for each individual sale.

7. Operating Expenses: The recurring expenses of operating your company, including rent, accountancy fees, software subscriptions, personnel, and customer service. As your company expands, controlling these costs helps safeguard your profit margins. 

8. Contribution Margin: The profit left after cost of sales, shipping, payment fees and advertising, before overheads. It shows whether each extra sale actually helps pay your fixed costs. 

9. Net Profit Margin: The portion of revenue that remains as profit after all costs, including operational expenditures, interest, and relevant taxes have been subtracted. This is one of the best ways to see how much money your eCommerce business really keeps from sales. 

Profits are not always correlated with high sales. You can identify where your money is going, manage expenses, and create a more successful eCommerce business by routinely reviewing these key numbers. 

What Is an eCommerce P&L and How Is It Different from a Standard One?

An eCommerce P&L (profit and loss statement) shows how much your eCommerce business earns, spends and keeps over a set period. Unlike a standard P&L, it includes marketplace commissions, returns, packaging, delivery and payment processing fees, which can quickly erode profit even when sales are rising.

To learn more about e-commerce profit margins, read our blog: E-commerce Profit Margins.

How an eCommerce P&L Is Laid Out for a UK Business

eCommerce profit and loss begins with sales at the top and subtracts costs in stages. So you can see where margin is made or lost at each level. Here is the layout for a UK eCommerce business. 

Line	What it contains	UK-specific notes
Gross sales	Total value of orders placed	Record net of VAT. VAT is collected for HMRC, so it is never revenue.
Less: discounts, returns and refunds	Promo codes, markdowns, refunded orders	Under the Consumer Contracts Regulations 2013, online customers generally have 14 days to cancel , so returns are often higher than in other retail channels.
= Net sales (turnover)	Revenue after the above	“Turnover” is the term used in UK statutory accounts.
Less: cost of sales (COGS)	Product cost, inbound freight, import duty, packaging, pick-and-pack	Since Brexit, customs duty on EU/rest-of-world imports is a real cost. Import VAT is normally recoverable if you are VAT-registered, so it should not sit in COGS.
= Gross profit	Net sales minus cost of sales	Gross margin % = gross profit ÷ net sales.
Less: distribution fulfilment and payment costs	Outbound shipping, courier fees (Royal Mail, DPD, Evri), third-party logistics, pick and pack, warehousing, payment processing (Stripe, PayPal, Shopify Payments)	The Companies Act formats show these as “distribution costs”. Some businesses put shipping in COGS instead, so pick one treatment and stay consistent.
Less: marketing and selling costs	Paid ads, affiliate commissions, marketplace fees (Amazon, eBay)	Many operators show a contribution margin subtotal here, which is the profit left after all variable costs.
Less: administrative expenses	Salaries, employer’s NI and pension contributions, software subscriptions, rent, accountancy and legal fees, insurance	Employer’s NI is 15% above the secondary threshold since April 2025. Auto-enrolment pension contributions also belong here
= EBITDA	Operating profit before depreciation and amortisation	An internal measure, not a statutory line.
Less: depreciation and amortisation	Equipment, website build costs
= Operating profit	Profit from trading
Less: interest and finance costs	Loan interest, merchant cash advance and stock finance charges
= Profit before tax
Less: corporation tax	Tax on profits	Companies pay 19% on profits up to £50,000 and 25% above £250,000, with marginal relief in between. Sole traders and partnerships pay income tax and Class 4 NI instead, so this line looks different.
= Profit after tax (net profit)	What remains for retained earnings or dividends

eCommerce P&L Example: A Worked UK Retailer Breakdown

Sample P&L for “Northfield Home”, a fictional UK homeware retailer. Figures are illustrative, in pounds, net of VAT, for the 12 months to 30 September 2026. 

Line	£	% of net sales
Gross sales	500,000
Less: discounts, returns and refunds	(70,000)
Net Sales	430,000	100.0%
Cost of sales	215,000	50.0%
Gross profit	215,000	50.0%
Distribution costs	38,000	8.8%
Payment processing fees	9,000	2.1%
Margin after shipping and fees	168,000	39.1%
Advertising and other marketing	68,000	15.8%
Contribution margin	100,000	23.3%
Administrative expenses	(73,000)	17.0%
EBITDA	27,000	6.3%
Depreciation and amortisation	(5,000)
Operating profit	22,000	5.1%
Interest	2,000
Profit before tax	20,000	4.7%
Corporation tax (19%)	3,800
Profit after tax	16,200	3.8%

How will it be read?

1. Gross to net sales: discounts and returns remove £70,000, or 14% of gross sales. Track this monthly, because any rise flows straight down the page.

2. Gross margin (50%): a pricing and sourcing signal. A fall usually means higher supplier costs, import duty, a weaker pound or heavier discounting.

3. Contribution margin (23.3%): shows whether growth pays. Advertising at 15.8% of net sales is the swing factor, with payment fees adding a further 2.1%.

4. Overheads: £73,000 of admin costs against a 23.3% contribution margin gives an EBITDA break even of about £313,000 in net sales, roughly 73% of current sales. Once depreciation and interest (£7,000) are included, the total fixed cost is £80,000 and break even rises to about £344,000.

5. EBITDA vs operating profit: EBITDA (£27,000) ignores depreciation, so operating profit (£22,000) is the truer measure of trading.

6. Tax: profit under £50,000 is taxed at 19%, giving £3,800. Sole traders pay income tax and Class 4 NI instead.

UK-specific traps that distort your P&L 

Relying on default platform dashboards can quickly mislead you about your real performance as you grow a UK eCommerce business. The tax and marketplace characteristics unique to the UK have a significant impact on eCommerce transaction flows, which are extremely layered and indirect. 

Here are six UK-specific traps that skew an eCommerce Profit and Loss (P&L) statement:

1. VAT treated as revenue or cost: Keep track of all sales and cost lines net of VAT if you are registered for VAT. You must register once your VAT taxable turnover over any rolling 12 months exceeds £90,000, or you expect it to in the next 30 days; below that, registration is voluntary. Revenue is overstated by gross sales that include 20% VAT. Unrecoverable VAT is a true expense and should be included on the appropriate expense line.VAT is commonly applied to marketplace fees (Amazon, eBay. Record them and reclaim the VAT. 
   
2. Import VAT mixed into cost of sales: VAT-registered businesses can use postponed VAT accounting to record import VAT on their VAT return and recover it as input tax on the same return. Duty and other import charges are separate costs. Include them in the landed cost within cost of sales. And if you have not registered for VAT, you pay import VAT and cannot reclaim it. Therefore, it becomes a real cost.  Source: GOV.UK, VAT on imports .

3. Assuming small parcels stay duty-free: Goods worth £135 or less currently enter the UK free of customs duty, though VAT applies at the point of sale. That relief is being removed, by October 2028 at the latest, and sellers and marketplaces will become liable for duty. Build duty into your landed costs now. Source: GOV.UK, Reforming the customs treatment of low value imports 

4. Understated returns and refund costs: When you merely record the net cash refunded to a customer and ignore the unrecoverable costs associated with the transaction, you are understating returns and refund costs. In the high-return retail environment of the UK, neglecting to account for non-reclaimable marketplace commissions, wasteful outbound shipping, and reverse logistics expenses artificially inflates your Net Sales and hides the real financial cost of product churn on your gross margins.  

5. Stock overstated and cash ignored: Stock that moves slowly or is damaged should be written down to the lower of cost and net realisable value. Stock purchased ahead of time, payment processor reserves, and VAT owed to HMRC all have an impact on cash without showing up in the eCommerce P&L. 

6. Wrong tax line for your business type: A limited company shows corporation tax below profit before tax, with dividends after that. A sole trader or partnership has no tax line in the P&L. Income tax and Class 4 NI are personal, and money taken out is recorded as drawings. 

Profit isn’t cash: why a profitable P&L can still leave you short 

Cash is the vital component of daily operations, while profit is a trailing accounting number. Due to timing discrepancies between accounting entries and actual cash flow, a UK eCommerce company may exhibit a strong net profit on its P&L while concurrently running out of money in the bank. 

Here is why a profitable P&L can still leave you stressed: 

• The Inventory Cash Trap: The cost of inventory is only recorded in a P&L after an item is sold (as Cost of Goods Sold). Your money is locked up and lying on shelves rather than in your bank account since it totally conceals the money you spent weeks or months before purchasing upfront bulk supplies. 

• Delayed Marketplace Payouts: Even if you make thousands of pounds in sales today, platforms like Amazon or TikTok Shop frequently hold onto your funds for a payout period or reserve. Your P&L marks the sale immediately, but your bank account remains empty while your suppliers demand payment.

• The VAT Accrual Deception: Your eCommerce P&L might look highly profitable because it eliminates VAT to show net figures. However, that collected VAT remains in your bank account as temporary cash until your quarterly HMRC VAT bill drops, creating a false sense of financial security.

• Upfront Ad Spend Scaling: In order to attract clients, paid traffic platforms such as Google and Meta immediately charge your credit card. Your upfront cash outflow for advertisements may easily exceed the postponed cash returns from those new sales if you are growing quickly, resulting in an unexpected liquidity crunch. 

Red flags to look for in your P&L (checklist) 

Sales

• Returns and refunds are growing faster than sales
• Discounts are creeping up
• Sales include VAT (if VAT-registered, revenue should be net of VAT)
• Marketplace sales are shown net of fees

Gross margin

• Gross margin has fallen for two or more periods
• Import duty and freight are missing from cost of sales
• Import VAT is sitting in cost of sales (it is normally recoverable)
• Slow-moving stock has not been written down

Shipping costs in P&L 

• No separate line for shipping expenses is displayed anywhere.
• In certain months, outbound shipping is included in the cost of sales; in other months, it is included in the cost of distribution (choose one approach and remain consistent).
• The percentage of net sales that goes for shipping is increasing.
• Customer shipping revenue is combined with product sales to conceal the actual cost of shipment.
• Instead of distribution costs, return postage is concealed in marketing or administrative expenses. 

Marketing and selling costs 

• Ad spend is rising without a matching rise in sales
• Contribution margin is shrinking
• Payment processing fees are missing or netted off sales

Overheads

• Employer NI is left out (15% above £5,000 a year for 2026/27, per GOV.UK)
• Employment Allowance is assumed but not claimed, or assumed when ineligible (single-director companies cannot claim it)
• Employer pension contributions are missing
• Admin costs are growing faster than contribution
• EBITDA is quoted without operating profit

How often should you review it? 

Check a few numbers weekly, do your main eCommerce P&L review monthly, and review VAT and tax each quarter. 

Weekly (10-15 minutes)

• Net sales and returns rate
• ROAS against break-even ROAS
• Shipping costs as a % of net sales
• Bank balance against your cash forecast

ROAS vs Profit

• ROAS (revenue from ads ÷ ad spend) measures sales, not profit.
• Break-even ROAS = 1 ÷ margin after shipping and fees. Northfield keeps 50.0% after cost of sales, loses 8.8% to distribution and 2.1% to fees, leaving 39.1%. So 1 ÷ 0.391 ≈ 2.6. 
• A ROAS above break-even still has to cover overheads before it becomes net profit.
• Use net sales, since platform figures may include VAT or ignore returns.

Monthly (the main review)

• Close the books within the first 1-2 weeks of the following month.
• Compare each line as a % of net sales against the previous month and the same month last year.
• Check gross margin, contribution margin and operating profit.
• Compare actual ROAS with break-even ROAS by channel.
• Run through the red-flag checklist.
• Check stock levels and write down slow-moving items.
• Reconcile profit to the change in bank balance, using the cash flow statement.

Quarterly

• VAT returns are usually due every 3 months, so align a review with each one.
• Check that VAT collected and reclaimed matches your P&L, and that cash is set aside for the payment.
• Recalculate break-even ROAS if prices, shipping or supplier costs changed.
• Update your forecast and break-even point.
• Review pricing, supplier costs and import duty.
• Revisit your 13-week cash forecast.

Annually

• Corporation Tax: for taxable profits up to £1.5 million, payment is due 9 months and 1 day after the accounting period ends. Source: GOV.UK
• Accounts: a private company’s accounts are due at Companies House 9 months after year-end, and the Company Tax Return (CT600) 12 months after.
• Review the year with your accountant, including stock valuation and depreciation.
• Check employer NI, the Employment Allowance and pension costs against the new tax year’s rates, which start on 6 April. Source: GOV.UK

Rule of thumb

• Check cash and ROAS weekly, profit monthly, tax and VAT quarterly, and the full picture annually.

Get help turning your P&L into decisions

Improving profitability starts with understanding your eCommerce P&L. Making smarter decisions about product pricing, inventory, advertising expenditures, and operating costs is the next step. eCommerce companies may better understand their financial performance, pinpoint areas for development, and confidently plan for long-term growth with the assistance of E2E accounting. 

FAQs: Frequently Asked Questions

Conclusion 

A helpful tool for determining what to do next is your eCommerce P&L. It can assist you in determining whether your pricing is cost-effective, whether advertising is producing profitable sales, and whether growing costs are impacting your profit margins. You can see more clearly what’s working and where your company needs improvement by monitoring these figures on a monthly basis. 

The goal isn’t simply to report profit but to understand what drives it. Our eCommerce Accountant can help you interpret your financial results and use them to guide everyday decisions, manage costs and plan for sustainable growth.

This guide is general information, not tax or accounting advice. Rates, thresholds and deadlines are for the 2026/27 tax year and can change, so check GOV.UK or speak to your accountant before acting.