Where the roles diverge
A great ecommerce accountant is a compliance and reporting specialist. They produce the numbers, file the returns, and make sure the company stays on the right side of HMRC. A fractional CFO is a decision-making specialist. They take those numbers as the starting point and use them to choose between paths: where to spend, where to cut, how to fund the next inventory cycle, whether to raise.
| Fractional CFO | Ecommerce accountant | |
|---|---|---|
| Primary output | Decisions made | Numbers produced |
| Owns year-end accounts | No | Yes |
| Owns VAT returns | No | Yes |
| Owns contribution margin rebuild | Yes | No |
| Owns cash forecast and fundraise readiness | Yes | No |
| Typical fees | £3.5k to £9.5k / month | £300 to £1,500 / month for a UK D2C brand |
When to use which
Under roughly £1m of revenue, a strong ecommerce accountant on a tidy Xero ledger with A2X for marketplaces is usually enough. The numbers are small enough that a founder can carry the strategic thinking themselves and the cost of a CFO retainer outweighs the marginal decision quality.
Above £1m, two things start to change. The cost of a bad pricing or inventory decision rises faster than revenue, and the founder’s time is the binding constraint. That is the moment a fractional CFO begins to pay for themselves: not by replacing the accountant, but by sitting on top of the work the accountant produces and turning it into decisions the founder no longer has to make alone.