Most growing haulage businesses end up as limited companies - for liability, for credibility with shippers, or because the accountant said so years ago. With the limited company comes a different tax animal: Corporation Tax, paid by the company on its profits. Unlike the owner-driver’s Self Assessment, this is the company paying its own tax bill, and the rates changed shape in recent years in a way that matters to mid-size fleets.
GOV.UK’s Corporation Tax overview is direct: Corporation Tax is a tax your company or association pays to HMRC on profits in an accounting period, and the amount depends on how much profit you make. It applies to profits from doing business as a limited company - and also to foreign companies with a UK branch or office, and to clubs, co-operatives and other unincorporated associations, though for this industry’s purposes the limited company is the case that matters.
The overview also notes you may be able to get allowances and reliefs - the capital allowances on trucks and trailers being the obvious transport example, where the timing of vehicle purchases interacts with the year’s profit figure.
HMRC’s published rates and allowances table gives the current structure. The small profits rate - for companies with profits under £50,000 - is 19%. The main rate - for companies with profits over £250,000 - is 25%. Between those two profit levels, Marginal Relief applies, with the Marginal Relief lower limit at £50,000 and the upper limit at £250,000.
What that means in practice: a one-depot operator making £40,000 profit pays 19%. A regional fleet making £300,000 pays 25% on the lot. And a business landing between the two - say £120,000 profit, a typical good year for a mid-size haulier - sits in the Marginal Relief band, where the effective rate climbs gradually from 19% toward 25% rather than jumping in one step. The band is wide enough that most growing fleets pass through it, so the years of expansion are the years the effective rate quietly rises.
Because the tax runs on profit, not turnover, everything upstream of the profit line matters: what the wagons cost to run, what can be claimed, and how the accountant times the big purchases. A haulage business can turn over seven figures and pay the small profits rate if the margin is thin - and plenty of haulage margins are exactly that thin. Equally, a good year with firm rates and full trucks can push a business through the £50,000 threshold faster than the owner expected, and the first hint should not be the tax calculation after year-end.
Corporation Tax runs on the company’s accounting period, not the personal tax year - a distinction that trips up directors who think in April-to-April terms. The company’s year-end sets the clock for working out profits, filing and paying, and the deadlines hang off it. Keep the company’s accounting dates in the same calendar as the O-licence renewal and the MOT schedule, because they all arrive whether or not anyone is watching.
The structural point new company owners miss: the company’s profit is not the director’s money until it is taken out, and Corporation Tax is the company’s own bill, separate from whatever personal tax the director pays on salary or dividends. The company pays HMRC on its profits in the accounting period; the director’s personal position is a different return on different rules. Keeping those two wallets separate - in the bank account, in the bookkeeping and in the head - is the discipline that makes the Corporation Tax side boring, and boring is what you want from a tax bill.
For owner-managed fleets, the rate structure is also the backdrop to every contract decision - more work at thin margin grows turnover, but only the profit line moves the tax position.
Three practical consequences fall out of the rate structure. First, the Marginal Relief band rewards planning: a business drifting up through £50,000 to £250,000 profit should know its effective rate each year, not assume last year’s. Second, allowances and reliefs - flagged in the overview itself - are the legitimate lever on the profit figure, and vehicle-heavy businesses have more of them than most. Third, the jump from 19% to 25% across the structure is large enough that profit-level conversations belong in the board calendar, not just the accountant’s inbox.