Aug 19

2026

Patent Box explained: when the 10% rate is worth claiming for a manufacturing or engineering business

The UK Patent Box can reduce the effective Corporation Tax rate to 10% on profits attributable to qualifying patented inventions and other eligible intellectual property. With the main UK Corporation Tax rate at 25%, the potential saving can be significant for profitable manufacturers and engineering businesses.

The relief is not limited to royalty income. Income from products incorporating a qualifying patented invention can also fall within the regime, subject to the Patent Box calculation and development requirements.

What actually qualifies?

A company generally needs qualifying intellectual property, relevant income and sufficient involvement in developing the underlying innovation. Qualifying rights include certain UK and European patents and other specified IP rights.

Income can include sales of patented products, sales of products incorporating patented components, licence income and certain infringement damages. Businesses undertaking innovation should therefore consider Patent Box alongside what qualifies for R&D tax credits in the UK and Ireland. SCC’s specialist tax relief and incentives team can assess how the regimes interact.

Ireland’s Knowledge Development Box has produced an effective 10% rate since 1 October 2023 and currently applies to qualifying accounting periods commencing before 1 January 2027.

How the Patent Box calculation works

Patent Box does not simply apply 10% to all company profits. Businesses must identify relevant IP income and allocate expenditure appropriately. The calculation can include deductions for routine returns and marketing assets before applying the R&D nexus fraction.

Accurate product-level records are therefore important. Good monthly management accounts can make income and expenditure easier to trace, while SCC’s SME business advisory team can help establish suitable reporting.

The commercial value of a claim depends on the amount of qualifying profit, compliance costs and how long the intellectual property is expected to generate income. There is no universal profit threshold at which Patent Box becomes worthwhile.

Businesses should apply the same cost-benefit analysis to capital allowances on plant and machinery.

Where claims can go wrong

Common problems include failing to elect within the permitted period, inadequate income streaming and insufficient evidence of the company’s development activity.

Patent Box also does not follow automatically from an R&D tax relief claim. The regimes have separate statutory requirements, and the 2026 R&D changes should be considered separately.

Good documentation is essential if HMRC reviews a calculation. The evidential discipline used by forensic accounting specialists can be equally valuable when supporting complex tax positions.

Patent-pending income can also be important. Following grant, qualifying profits arising during the patent-pending period can potentially be brought into Patent Box for up to six earlier years, provided the required elections and conditions are satisfied.

If you trade in the UK and Ireland

An Irish company cannot simply use the UK Patent Box. Businesses setting up a company in both the UK and Ireland should consider where intellectual property is owned, where qualifying R&D takes place and which company earns the resulting income.

SCC’s cross-border accounting and tax advisers can examine both regimes. Where margins are already under pressure, the business recovery and restructuring team can also help prioritise cash-flow and tax decisions.

HMRC’s latest published estimate indicates that around 1,650 companies elected into Patent Box for 2023–24, with approximately £1.977 billion of relief. Manufacturing groups received an estimated 41% of the total relief.

Frequently asked questions

Does a patent have to be granted before Patent Box relief is available?

Relief is generally dependent on a qualifying right being granted, although qualifying patent-pending profits may subsequently be included subject to the statutory rules.

Is Patent Box the same as R&D tax relief?

No. R&D relief supports qualifying development expenditure, while Patent Box applies a reduced effective tax rate to qualifying IP profits.

Where can businesses check the official rules?

See Patent Box from HMRC and the Knowledge Development Box from Revenue.

If your business owns qualifying intellectual property or is considering a patent application, talk to the team at SCC Chartered Accountants about whether Patent Box is commercially worthwhile for your circumstances.