Ecommerce & Digital
Why Your Ecommerce Business Needs a Finance Function Before It Thinks It Does
1 August 2025
Ecommerce businesses tend to invest in the things that are visibly connected to revenue: product development, marketing, platform optimisation, fulfilment capability. Finance infrastructure gets treated as a cost that follows success rather than a capability that enables it.
This sequencing is understandable. It is also expensive, in ways that only become clear when something goes wrong.
What happens without finance infrastructure
The margin story is fiction. An ecommerce business without a proper finance function typically knows its revenue reasonably well and its costs approximately. The margin it believes it is generating is the gap between those two numbers. It is usually wrong, because the costs that are easiest to miss are the ones that erode margin most: the advertising spend that is tracked by the platform but not reconciled to the bank, the return costs that are netted against revenue rather than shown as a separate line, the storage fees that accumulate quarterly, the payment processing spread that nobody has ever calculated at the order level.
The real margin is almost always lower than the believed margin. A properly structured ecommerce P&L reveals the gap. Sometimes it is small. Sometimes a business discovers it has been trading at a loss for eighteen months.
The cash position is a surprise. Ecommerce cash flows are more complex than they look. Revenue comes in quickly through the platform or payment processor. Costs go out on various cycles: advertising daily or weekly, fulfilment as orders ship, stock monthly or quarterly, platform fees on a defined schedule. The interaction between these cycles, particularly in a seasonal business or a fast-growing one, produces cash positions that differ from the P&L picture significantly.
A business without a cash flow forecast, built as part of proper ecommerce budgeting, does not know it is running out of cash until it has. By then the options are limited.
Tax compliance accumulates. VAT, corporate tax, payroll taxes: these obligations do not disappear because they have not been managed. An ecommerce business that has been trading for three years without proper finance management may have historic tax exposure in multiple jurisdictions. Discovering this during a funding process, an acquisition, or a tax audit is significantly more expensive than managing it correctly from the start.
What basic finance infrastructure looks like for an ecommerce business
At the early stage, the minimum is a proper accounting system configured for the business model, a reconciliation between the ecommerce platform and the bank account run monthly, a simple management P&L by channel produced monthly, and a basic cash flow forecast updated weekly.
This does not require a Finance Director. It requires a competent bookkeeper or management accountant, the right systems, and someone at the top of the business who understands what the numbers should show and reviews them monthly.
The step up from that, as the business grows, is a channel-level P&L with contribution analysis by product, a proper inventory management system connected to the accounts, multi-jurisdiction VAT compliance if trading internationally, and knowing when to hire finance leadership who can turn the financial data into commercial insight.
The data asset question
A well-run ecommerce finance function generates data that is commercially valuable: customer acquisition cost by channel, lifetime value by cohort, contribution by product and by market, the return on every significant marketing investment. This data informs the decisions that determine whether the business grows profitably or grows in a way that destroys value.
A business without the finance infrastructure to capture and analyse this data is making its most important commercial decisions without the information it needs to make them well. The cost of that is not a line on the P&L. It is the opportunity cost of every suboptimal decision compounded over time.
Maebh Collins is a Chartered Accountant (FCA, ICAEW) who has built finance functions inside ecommerce businesses from the ground up and advised on finance infrastructure for fast-growing digital commerce operations. If you need ecommerce finance leadership, I can help.
Maebh Collins is a Chartered Accountant (FCA, ICAEW), Big 4 trained, with twenty years of experience building and running international businesses. She specialises in finance transformation, ecommerce operations, and digital strategy.