Patent Box

What is the Patent Box?

The Patent Box is a UK tax incentive that allows companies to apply a lower 10% corporation tax rate to profits attributable to qualifying patents. With the main corporation tax rate at 25%, this represents a significant reduction for companies that derive income from patented technology.

The regime was introduced in the Finance Act 2012 and took full effect from April 2013. It was reformed in 2016 to align with OECD guidelines under the nexus approach, which requires a link between the R&D activity and the patent income.

Who Can Use the Patent Box?

To elect into the Patent Box, a company must:

• Be liable to UK corporation tax
• Own or exclusively license qualifying IP rights
• Have undertaken qualifying development activity on the patented invention (or have contracted it out to a connected party)
• Make a valid election in its company tax return

The election applies from the start of the accounting period in which it is made and remains in effect until the company withdraws it.

Qualifying IP Rights

The Patent Box applies to profits from the following types of intellectual property:

A company can begin benefiting from the Patent Box only after the patent has been granted, though the benefit can be backdated to the date the application was filed, up to a maximum of six years.

Qualifying Income

The 10% rate applies to profits from qualifying residual profit (QRP), which includes income from:

• Sales of patented products or products incorporating patented technology
• Licence fees and royalties received from licensing patents to third parties
• Proceeds from patent sales (the capital gain element)
• Damages or compensation for patent infringement
• Notional royalties embedded in the price of products where a patent contributes to value

Income from products where the patent is incidental to the sale — rather than a core driver of demand — may not qualify in full.

How the Benefit is Calculated

The Patent Box benefit is calculated using a multi-step process set out in the Corporation Tax Act 2010:

Step 1: Identify Relevant IP Income

Determine the gross income streams attributable to qualifying patents.

Step 2: Deduct Routine Returns

Subtract a routine return of 10% on certain costs (such as capital allowances, staff costs, premises, and plant) to strip out profits unrelated to the patent.

Step 3: Apply the Nexus Fraction

The nexus fraction limits the benefit to the proportion of R&D that the company performed itself (or subcontracted to unconnected parties). The formula is:

(D + S1) × 1.3 / (D + S1 + S2 + A)

Where:

• D = qualifying R&D expenditure undertaken directly by the company
• S1 = R&D subcontracted to unconnected persons
• S2 = R&D subcontracted to connected persons
• A = cost of acquiring the patent (if purchased from another entity)

The 1.3 multiplier provides a 30% uplift on qualifying expenditure, capped at 100%.

Step 4: Calculate the Tax Benefit

The qualifying residual profit is then taxed at 10% rather than the main corporation tax rate. The company claims a deduction in its tax return equal to the difference.

Example

Interaction with R&D Tax Relief

The Patent Box and R&D tax relief are complementary and can be claimed simultaneously. R&D tax relief reduces the cost of developing the invention, while the Patent Box reduces the tax on profits once the invention generates income.

However, the nexus fraction means that companies which outsource most of their R&D to connected parties will receive a smaller Patent Box benefit. Keeping R&D in-house or subcontracting to unconnected third parties maximises both the R&D relief and the nexus fraction.

Making the Election

The Patent Box election is made through the company’s corporation tax return (CT600). Key points:

• The election is irrevocable for the accounting period once the return is filed
• It can be withdrawn for future periods by notifying HMRC
• A company can elect in or out from period to period, though frequent changes may attract HMRC scrutiny
• The company must have completed qualifying development activity before the election takes effect

Record-Keeping

Companies using the Patent Box should maintain detailed records of:

• Which patents generate qualifying income and the corresponding revenue streams
• R&D expenditure broken down by direct, subcontracted (connected and unconnected), and acquired categories
• The nexus fraction calculation for each relevant IP right
• Routine return deductions and the allocation of costs

HMRC may enquire into Patent Box claims, and inadequate records can result in the claim being denied.

Group Companies

Where a group of companies is involved, the Patent Box benefit is available to the company that:

• Holds the qualifying IP rights, or
• Holds an exclusive licence to exploit the patents

The company must also have performed qualifying development activity. If one group company holds the patent but another undertakes the R&D, arrangements may need restructuring to ensure the claiming company meets the nexus requirements.

When the Patent Box May Not Be Worthwhile

The Patent Box involves complex calculations and compliance requirements. It may not provide significant benefit where:

• Patent-related profits are small relative to total profits
• The company has significant losses that already eliminate its corporation tax liability
• Most R&D was acquired or subcontracted to connected parties, resulting in a low nexus fraction
• The cost of compliance (specialist advice, detailed tracking) exceeds the tax saving