from 6 April 2023, the way income tax payable by unincorporated businesses – such as sole traders or partnerships – is calculated changed under new rules brought in by HMRC.

However, the tax body is worried that many businesses still seem to have not heeded its warnings about how this may impact them. Put simply, some could pay much more in tax and be burdened with extra unnecessary admin too.

The change to what is known as the ‘basis period’ rules will make little or no difference to the many businesses that already have a 5 April or 31 March year-end. 
But as Emma Rawson, a Technical Officer at the ATT, points out, “for those with accounting years that do not align with the tax year, the impact will be significant”.

She explains that, unfortunately, “many businesses who could be hit by this change remain unaware of it. The resulting temporary increase in their tax bills, and ongoing additional admin burdens, could therefore come as a nasty shock”.

What has changed

Currently, once established, sole traders and partnerships pay income tax on the profits of their accounting year ending in the tax year. 

For example, if a trader draws up accounts to 31 December each year, in the tax year 2022/23 it will be taxed on profits for the previous year, ended 31 December 2022.

From April 2024, this all will change, and they will instead pay tax on the profits they actually earn in any one tax year. 

Emma notes that “tax year 2023/24 is a ‘transitional year’, in which the tax system swaps over from the current basis to the new tax year basis. To achieve this, special rules apply to calculate taxable profits and tax. 

Effectively, those that have a year-end other than 31 March or 5 April, will be taxed on their normal basis period, plus an extra amount of profits to bring them up to the end of the tax year”. 

So, a business with a 31 December year-end will be taxed on their profits for the year ended 31 December 2023, plus their profits for the period from 1 January 2024 to 5 April 2024.

Emma highlights that this will result in more than 12 months’ worth of profit being taxed in 2023/24. To help ease any additional tax arising as a result, she says that “businesses can offset any ‘overlap profits’ they may have from their early years of trading (when they may have been taxed twice due to how the old basis period rules work). They may also be able to spread any remaining ‘excess profits’ over up to five years”.

The problem outlined

As noted above, the transitional year rules could see a temporary increase in the tax payable by businesses without a 31 March or 5 April year-end. However, for Emma that is not the end of the story as these businesses will also experience additional administrative burdens.

In particular, she warns that once these changes come in, those that draw up accounts to something other than 31 March or 5 April will have extra work to do each time they complete their tax return: “To get to the profits for a tax year, they will need to combine amounts from two separate sets of accounts and, depending on how late the accounting date falls, the second set of accounts may not be ready by the time they file their tax return”.

Where this is the case, she says that “they will have to estimate the amount of profits to take from the second set of accounts and include a ‘provisional figure’ on the tax return. They will then need to amend the return to correct that provisional figure within one year of the original filing deadline (i.e. by 31 January 2027 for a 2024/25 return).”

Irritatingly, these extra steps are not a one-off but will re-occur every year, when they prepare their tax return.

Making the change

So, with the change set out, Emma says that the best way to avoid these ongoing issues is to change accounting date to 31 March or 5 April. 

Emma says that, luckily for the moment, it’s possible to change a business’ accounting date by drawing up a set of accounts for a shorter, or longer, period than usual, ending with the new accounting date. 

She says that the best time to make this change may be during the transitional year 2023/24. This is because “special rules applying in that tax year may allow them to ‘spread’ any excess profits they have to bring into account as a result over up to five years – something which isn’t available if they make the change in any other tax year.”

Beyond that, Emma explains that “another advantage of changing in 2023/24 is that the normal rule, which says a set of accounts can’t be longer than 18 months, is disapplied in that year. This means that they can draw up one long set of accounts to make the change”. In her view, “changing an accounting date to 31 March or 5 April will undoubtedly make a trader’s life easier from a tax perspective”.

Before making any business change, however, good advice is necessary to weigh up what’s best for the business overall alongside the tax-related issues.