Battle · 3 companies
Energy suppliers
Full power, or running on empty?
British Gas leads on 4 of the five measures that matter most: turnover, pre-tax profit, profit margin, growth and net assets. British Gas is the biggest by turnover at £14,523m, against £13,683m at Octopus Energy. British Gas keeps the most of every £100 it takes, £3.29 as pre-tax profit.
The year ends are up to 12 months apart, so this compares each company's most recent filing rather than the same twelve months. Octopus Energy and OVO Energy file group accounts that include subsidiaries; British Gas files for a single company, which flatters the groups on size.
Accounts compared: British Gas to Dec 2024 · Octopus Energy to Apr 2025 · OVO Energy to Dec 2025
The Numbers
| # | Company | Turnover | Change | Pre-tax profit | Margin | Employees | Pay per head | Turnover per head | Net assets | Bank and cash | Accounts to | Basis |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | British GasBritish Gas Trading Limited | £14,523m | -32.0% | £477m | 3.3% | 6,970 | £48,000 | £2.1m | £3,283m | £0.8m | Dec 2024 | Single company |
| 2 | Octopus EnergyOctopus Energy Group Limited | £13,683m | +10.1% | -£260m | -1.9% | 10,030 | £49,000 | £1.4m | £1,482m | £1,512m | Apr 2025 | Group |
| 3 | OVO EnergyOVO Group Ltd | £5,156m | -6.8% | £121m | 2.3% | 4,304 | £54,000 | £1.2m | £81m | £248m | Dec 2025 | Group |
Ranked by turnover. Click any column to sort. The leader on each measure is highlighted. Movements are against each company's own prior year. Pre-tax profit is filed except where marked (est.).
Category winners
Biggest by turnover
British Gas
£14,523m
Most pre-tax profit
British Gas
£477m
Highest profit margin
British Gas
3.3%
Fastest-growing turnover
Octopus Energy
+10.1%
Biggest employer
Octopus Energy
10,030 staff
Highest pay per head
OVO Energy
£54,000
Most turnover per head
British Gas
£2.1m
Largest net assets
British Gas
£3,283m
Most cash
Octopus Energy
£1,512m
The Takeaway
- British Gas converts the most of its turnover. Of every £100, £3.29 reaches pre-tax profit, against a loss of £1.90 at Octopus Energy.
- British Gas is the largest on the top line, £14,523m of turnover, 1.1x Octopus Energy's £13,683m.
- Octopus Energy is growing fastest, turnover +10.1% on its own prior year. British Gas and OVO Energy went backwards.
- Octopus Energy is the biggest employer with 10,030 people; OVO Energy pays the most per head, an average staff cost of about £54,000.
- British Gas has the largest balance sheet, net assets of £3,283m, while Octopus Energy holds the most cash at £1,512m.
Who keeps the most of every £100 of sales?
British Gas keeps the most: £3.29 of every £100 of turnover becomes pre-tax profit. Octopus Energy does worst, losing £1.90.
Every profit figure here is the one the company filed.
The chart splits each company's turnover into £100: what goes on people, on interest and on everything else, and what is left as profit.
Out of every £100 of turnover
Each column is £100 of that company's own turnover, so companies of any size compare on one scale; the figures are pounds out of each £100, not millions. Companies run from the best margin to the worst. Payroll is staff costs, financing is interest paid, other running costs are everything else, and profit is pre-tax profit, filed or estimated as marked in the table. A loss is not an extra cost: it is the part of the costs that runs past the £100 line, marked with a red bracket. Hover over any segment for its figure.
Who is the biggest, and does the comparison hold?
By turnover the order is British Gas (£14,523m), Octopus Energy (£13,683m), OVO Energy (£5,156m).
By headcount, Octopus Energy leads with 10,030 employees.
The comparison holds with the dates stated plainly: British Gas to Dec 2024, Octopus Energy to Apr 2025, OVO Energy to Dec 2025. The bases differ: group accounts include the businesses a company owns, single-company accounts do not.
Turnover on the latest filing
Who is growing fastest?
Octopus Energy grew fastest, turnover +10.1% on its own prior year, ahead of OVO Energy (-6.8%), British Gas (-32.0%).
Turnover change on each company's own prior year
Who employs the most, who pays the most, and who brings in the most per head?
Octopus Energy employs the most, 10,030 people, against 6,970 at British Gas.
OVO Energy has the highest average staff cost, about £54,000 a head; British Gas the lowest, about £48,000.
British Gas brings in the most turnover per employee, about £2.1m, against £1.2m at OVO Energy. It says as much about the business model as the workforce: a marketplace or a wholesaler needs far fewer people per pound than a restaurant or a gym.
Who owns each one?
Ownership as recorded on the Companies House register of people with significant control, in the bands the register uses.
Held by Gb Gas Holdings Limited
A company recorded as a person with significant control. 1 outstanding charge on the register.
Who owns British Gas →
Octopus Energy Group Limited · 09718624Held by Octopus Energy Topco Limited
A company recorded as a person with significant control. 10 outstanding charges on the register.
Who owns Octopus Energy →
OVO Group Ltd · 10722770Held by Ovo Holdings Ltd
A company recorded as a person with significant control. 7 outstanding charges on the register.
Who owns OVO Energy →
What does the full ledger show?
| Measure | British Gas | Octopus Energy | OVO Energy |
|---|---|---|---|
| Registered name | BRITISH GAS TRADING LIMITED | OCTOPUS ENERGY GROUP LIMITED | OVO GROUP LTD |
| Company number | 03078711 | 09718624 | 10722770 |
| Incorporated | 1995 | 2015 | 2017 |
| Accounts filed | 29 September 2025 | 9 January 2026 | 19 August 2026 |
| Turnover, prior year | £21,371m | £12,433m | £5,530m |
| Pre-tax profit, prior year | £1,370m | £78m | -£166m |
| Staff costs | £337m | £492m | £234m |
| Payroll share of turnover | 2.3% | 3.6% | 4.5% |
| Employees, prior year | 6,409 | 6,438 | 5,099 |
| Dividends paid | n/d | n/d | n/d |
| Charges outstanding | 1 | 10 | 7 |
A figure the filing does not disclose is shown as n/d; a zero in a filing is treated as not disclosed. Rounding: below £0.1m in thousands, £0.1m to £2m to one decimal place, above that to the nearest million.
Energy suppliers: common questions
Who is the biggest of British Gas, Octopus Energy or OVO Energy?
British Gas, with turnover of £14,523m in the year to December 2024.
Which makes the most profit?
British Gas: £477m pre-tax in the year to December 2024.
Which employs the most people?
Octopus Energy, with 10,030 employees in its latest accounts.
British Gas or Octopus Energy: which is bigger?
British Gas, with turnover of £14,523m against £13,683m at Octopus Energy on their latest filings. On margin, British Gas keeps more of each £100 as pre-tax profit. The full head to head is in the VS Series. Read the VS page →
British Gas or OVO Energy: which is bigger?
British Gas, with turnover of £14,523m against £5,156m at OVO Energy on their latest filings. On margin, British Gas keeps more of each £100 as pre-tax profit.
Octopus Energy or OVO Energy: which is bigger?
Octopus Energy, with turnover of £13,683m against £5,156m at OVO Energy on their latest filings. On margin, OVO Energy keeps more of each £100 as pre-tax profit.
Where do these figures come from?
Each company's latest accounts filed at Companies House. Each links to its full Spark Intel profile, which names the filing it comes from.
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