There is one number in this Budget that almost every finance team can already predict, and it is the one the board will ask about first. The main rate of corporation tax is staying at 25%. The government committed to capping it there for the whole Parliament, alongside keeping full expensing and the Annual Investment Allowance, and the new Chancellor has reportedly said he will stick to those pledges.
That stability is welcome, but it is also a trap. If the headline rate is fixed, the pressure on the public finances has to land somewhere else, and for most businesses that somewhere else will matter far more to their 2027 year-end than the rate ever would.
On 28 October, John Healey delivers his first Budget, and the first of Andy Burnham's government, just over three months into its term. A new Chancellor, a new prime minister and an open question over whether tax rises are needed to fund their plans add up to a wider range of plausible outcomes than any Budget in recent memory. Reform of business rates, including Small Business Rates Relief, has already been promised. Updates on the next phase of Making Tax Digital are expected. The corporate tax outlook looks calm on paper, but the total cost of running a business is anything but settled.
That creates a timing problem finance teams don't talk about enough. For a company with a 31 March year-end, there are roughly five months between Budget day and the books closing. That is the whole planning window for FY27: when to commit capital spend, how to balance salary and dividends, what to provide for, and whether to bring decisions forward before measures take effect in April 2027. Five months sounds generous. It isn't, if the first month goes on rebuilding forecasts.
And for many businesses, that is exactly where the first month will go. In our recent survey of 170 finance professionals, a third said building what-if scenarios is one of their biggest challenges, and 45% lose significant time simply updating the data in their models. 42% still model on spreadsheets alone. Put those numbers next to a Budget with this many moving parts and you can picture 29 October in most finance teams: the board wants to know what it means for the business, and the honest answer sits in a model someone now has to rework by hand.
So what should finance teams and business owners be doing in the next few days?
First, build the scenarios now. Model at least two versions of FY27: one where the Budget is broadly neutral for your business, and one where the pressure lands on the costs you are most exposed to, whether that is business rates, employment costs or a relief you rely on. When the Red Book lands, you are choosing between scenarios you have already built, not starting from a blank sheet.
Second, sort the time-sensitive decisions from the ones that can wait. Some year-end moves only make sense if they are made before a measure takes effect. Others are far better held until the details are published. Your plan should say which is which before 28 October, so nobody is making a rushed call in March that should have been made in November.
Third, use the stable corporation tax rate as the anchor it is. With the headline rate capped and full expensing retained, investment planning has a fixed point to build around. The variable for most businesses this year is cash flow, so that is where the modelling effort should go. A business that knows its tax rate but not its cash position in March has only half the answer.
None of this requires predicting the Budget. It requires accepting that nobody can, and preparing for more than one outcome. That is a modelling discipline, and it is one finance teams have been squeezed out of by the sheer effort of keeping their spreadsheets alive.
The businesses that come out of this Budget well will be the ones whose finance team can sit down with the board on Thursday morning and explain what 28 October means for their year-end, with the numbers already in front of them. In a Budget where the headline rate is the safest bet on the table, that is where the real value is.