UK corporation tax explained: what every Arab company director needs to understand

Corporation tax is the tax your UK limited company pays on its profits. The current rates are 19% on profits up to £50,000 (the small profits rate) and 25% on profits above £250,000. Profits between those thresholds are taxed at a marginal rate that blends the two. For most small UK companies owned by Arab directors, the 19% rate applies, and the actual liability is often modest. But modest doesn't mean optional.

Your personal tax residence and the company's tax residence are separate questions. UK incorporation normally makes a company UK tax resident under domestic law. While it remains UK resident, UK Corporation Tax generally applies to its worldwide chargeable profits, not only income from UK customers. If the company is also tax resident in another country, the applicable treaty and the facts may change its UK residence and tax position. Where the director lives does not settle either question on its own.

The filing timeline matters as much as the rate. Your CT600 corporation tax return is due 12 months after your accounting period ends. But your tax payment is due 9 months and 1 day after the period ends, a full three months before the return. If your year ends 31 March 2026, the tax must be paid by 1 January 2027. The return isn't due until 31 March 2027. Directors who wait until the return deadline to calculate their liability often find they've already owed interest on a late payment for three months.

Dormancy is something you tell HMRC, not something that happens by itself. If HMRC has issued a notice to deliver a return, that notice must be dealt with even for a period with no profit: it does not lapse because nothing happened. Once you have told HMRC the company is dormant and they have accepted it, no further annual return is due merely because the company exists, until trading resumes or HMRC asks again. Companies House is separate and still wants dormant accounts every year. Once you've told HMRC your company is dormant, they won't expect a CT600 for that period. But if you've never told them, if your company has been sitting unused for three or four years with no communication, HMRC may have outstanding CT600 obligations logged against it that you've been unaware of. This is one of the most common compliance gaps we find when clients come to us after years of inactivity.

The practical side: corporation tax is calculated on profits, which means allowable expenses reduce your liability. For a Arab-owned UK company, typical deductible expenses include registered office fees, accountancy fees, director ID verification costs, professional subscriptions, and any UK operating costs. Keeping proper records throughout the year, not scrambling at year end, means the accounts are accurate, the liability is correctly calculated, and the CT600 is filed without surprises.