Calculus EIS Fund

The Calculus EIS Fund is the longest-running EIS fund, having been the first to launch in 1999. 

Since then, the fund has invested over £230 million into 105 companies. Under its current strategy (adopted in 2013/14) the fund has invested £184 million in 74 companies.

The fund targets EIS-qualifying companies at a later stage, ideally once they are more mature and could potentially have lower failure rates and shorter holding periods compared to startups or an early-stage portfolio. However, like all EIS investments, they are still high risk. Investors can expect a minimum portfolio of five companies.

Important: The information on this website is for experienced investors. It is not advice nor a research or personal recommendation to invest. If you’re unsure, please seek advice. Investments are for the long term. They are high risk and illiquid and can fall as well as rise in value, so you could get back less than you invest.

Read important documents and apply


  • Evergreen EIS fund 
  • Established in 1999
  • Aims to invest in growth-focused, mature unlisted businesses 
  • Focus on fast-growing sectors
  • Target return of 2.5x  with exits targeted after 3-5  years – not guaranteed 
  • Strong and experienced management team 
  • The fund targets a minimum portfolio of five  companies with advance assurance
  • £30,000 minimum investment
  • Quarterly closes, with funds aiming to be fully deployed within 15- 18 months (not guaranteed)

The manager

Calculus Capital’s CEO and Chairman, John Glencross and Susan McDonald, made their first EIS investment in 1996. They founded Calculus Capital in 1999 and shortly after launched the UK’s first approved EIS fund. Calculus now manages £140  million in tax-efficient investments, split between this EIS fund, its VCT, and the media-focused Calculus Creative Content EIS Fund. 

The investment team is co-led by Alexander Crawford and Richard Moore who are responsible for sourcing and executing new deals, as well as advising portfolio companies. They are supported by a wider team of eight, including Dominic Harris, who acts as Head of Portfolio Management and monitors companies post-investment. Both EIS funds and the VCT are managed by the same team due to the similarity of their investment mandates. 

Investment strategy

The Calculus EIS Fund is an evergreen offer that predominantly targets more mature private growth companies, rather than earlier-stage businesses. The main reason for this is the expected risk/return profile: failure rates for more established businesses tend to be lower, and the time to exit shorter, although these are still young EIS-qualifying businesses, so like all EIS investments, they are by nature higher risk.

The investment team targets investments into fast-growing sectors, currently with a bias towards technology, healthcare and media, where it believes the most compelling opportunities can be found. The fund is unlikely to invest in leisure or retail companies under current market conditions.  

The investment team looks for companies with the following characteristics : 

  • Proven and competitive products and services
  • Primary constraint to growth is access to finance
  • Strong management teams
  • A clear market need
  • A clear route to exit

A large proportion of investment opportunities come from Calculus’ investor base and management teams it has successfully backed in the past. Calculus Capital also benefits from its longstanding industry experience and its investment team’s personal networks of lawyers, advisers, and brokers.

On average, the investment team screens 700  deals a year, reviews around 150 companies and completes around 7 to 12 investments. 

When reviewing a deal, Calculus conducts its own comprehensive research then brings in external parties for in-depth financial, legal, and commercial due diligence.  

Once investments are made, Calculus aims to mitigate risk by actively managing its portfolio companies. Calculus initially creates a 100-day plan with each company and works together with the management to formalise the company’s strategy for the next 3-5 years. Calculus will also monitor performance closely through monthly management information packs and will provide ongoing support in areas such as executive coaching, strategy and financial planning. 

Target return

There is a target return of 2.5x over 5 years. This is a target and is not guaranteed.

Exit strategy

Calculus will actively look for potential exit options as soon as commercially possible after the end of the EIS three-year minimum holding period. In practice, it expects this to be four to five years from investment. Exits may be achieved through a variety of routes, including a trade sale, management buy-out, refinancing or IPO. Exits and timeframes are not guaranteed. 


Under the current investment strategy (adopted in 2013/14) , the Calculus EIS fund has invested a total of £184 million into 74 companies. 

Each investor is expected to hold a minimum portfolio of five companies with capital typically deployed over 15 to 18 months. 

Below are portfolio company examples from previous iterations of the fund. They are outlined to give a flavour of the types of companies you might expect but are unlikely to be part of a new investor's portfolio. 

Blue Wireless Technology – Calculus EISBlu Wireless Technology

Blu Wireless is a firm leading the way in bringing ultra-fast millimetre wave (mmWave) wireless technology into homes and businesses through the rollout of Wi-Gig® and 5G networks. Blu Wireless has many of the world’s leading semiconductor and consumer electronics companies among its customers.

One new client is First Group, the leading UK transport operator. The deal will allow Blu Wireless Technology to introduce advanced wireless access across First Group services. It is anticipated this should increase data capacity available to train passengers by over 100x.

Calculus first invested in 2017 as part of a £6.6 million institutional and private investment round following the strategic investment round lead by ARM, the UK semiconductor and software design company earlier in 2017. Calculus provided follow-on funding in 2019 after the company demonstrated commercial success, winning a number of government and private contracts. In total, the EIS fund has invested £5 million into the company.

rotageek - Calculus EIS FundRotageek

The idea for Rotageek came from Chris McCullough’s experience as an emergency doctor in the NHS. His schedule fluctuated between being too rigid and not knowing where he was working week to week . In an attempt to address this, Chris started working on a solution with Roy Pounder (a fellow doctor), and Nick Mann (an IT consultant) . This would eventually become Rotageek, now an award-winning scheduling platform.

Today, Rotageek offers companies a complete workforce management solution – from a simple digital rota to using machine learning algorithms to predict future demand. The company has established a strong position in the UK retail sector with customers such as O2, Pret a Manger, and Pets at Home. The company is also expanding into the healthcare market, having won a contract with Ashford and St Peter's hospitals, to produce first-of-its-kind demand-led rostering to the NHS.

Calculus invested £2 million into the company through its VCT and EIS fund in 2020. The investment was part of a wider £6 million fundraising round, alongside Mobeus and angel investors. The funding is intended to help the company continue its expansion into the healthcare industry as well as securing further partnerships with retailers in the UK and abroad.

ActiveOps - Calculus EIS FundActiveOps (example of previous exit) 

ActiveOps is a market leader in management process automation.

Its software allows managers to simplify the running of operations and increase worker productivity through data collection and real-time reporting. The business targets clients predominantly in the banking, insurance, and business processing and outsourcing sectors. It currently has approximately 100,000 individual users worldwide, including blue-chip clients such as Nationwide, TD Bank, and Capita. 

Calculus first invested £4.7 million in the business in 2014, acquiring a stake of approximately 30%. Over the following five years revenues increased significantly from £7 million in March 2015, to £20 million in March 2020. The company completed its IPO on AIM in March 2021, valuing the business at £120 million. Past performance is not a guide to the future.

Origin Broadband (example of previous failure)

As with any high-risk investment, not all turn out well. One such example is Origin Broadband. Originally based in Doncaster, Origin is a national telephone and broadband provider. The company was founded in 2011 and at one point claimed to be the UK’s sixth largest broadband provider. Between 2016 and 2018 the company saw its client base grow from 4,000 to 36,000, however, its operational systems struggled to cope with the rapid increase in demand. By December 2018 the firm had to cut a significant number of jobs as a result of ‘bad debts, increased staff costs and weak cost control’.

Despite a number of proactive measures to curb losses, Calculus decided the company would require extensive funding to support it up to profitability. Consequently, the EIS fund sold its holdings to a private investor resulting in a loss or flat return on investment (depending on tranche).


The manager has to date not supplied performance details in the format used for other EIS offers on this website. 

Risks – important

This, like all investments available through Wealth Club, is only for experienced investors happy to make their own investment decisions without advice.

EIS / SEIS investments are high-risk so should only form part of a balanced portfolio and you should not invest money you cannot afford to lose. They also tend to be illiquid and hard to sell and value. Before you invest, please carefully read the Risks and Commitments and the offer documents to ensure you fully understand the risks. 

Tax rules can change and benefits depend on circumstances.

This EIS fund invests in early-stage businesses which are more likely to fail than larger ones. So you should expect a number of failures in the portfolio, or even be prepared for all companies to fail.

Calculus Capital has an exclusive focus on EIS and VCT investments, both of which are subject to HMRC rules which can change frequently. This could leave the firm and its investee companies vulnerable if rules change unfavourably in future.


A summary of the main charges and savings is shown below. Some of these will be payable by the investor, whilst others by the investee companies. The investment may have additional charges and expenses: please see the provider documents, including the Key Information Document, for more details.

Investor charges
Full initial charge 4%
Wealth Club initial saving 1% (2% for existing investors)
Net initial charge through Wealth Club 3% (2% for existing investors)
Annual management charge 2%
Administration charge
Performance fee 20%
Investee company charges
Initial charge Variable
Annual charges Variable
All fees and charges are stated exclusive of VAT, which may be applicable in some cases. Any fees and charges payable by the investee companies or the underlying businesses do not directly come out of your investment. However, they will effectively reduce the returns generated by investee companies and therefore impact your investment.

More detail on the charges

Timing of the offer

The fund anticipates taking 15-18 months to fully deploy investor capital following the closing dates. However, it may take longer.

The next tranche deadline for the fund is 29 October 2021.

Our view

The Calculus EIS Fund is the longest-running EIS fund. Its team has ample experience in the tax-efficient sector: the two co-founders have been active in the EIS space for more than two decades. 

The fund targets later-stage investments in an effort to minimise failures and time to exit, however, as with any EIS investment, it is still high risk. The fund will focus on high-growth sectors and is expected to have a bias towards the technology, healthcare and media sectors. While these broad sector exposures may provide additional diversification to the offer, the investment team must ensure it has sufficient resources to evaluate opportunities across multiple sectors. The investment team appears well resourced and Calculus appears to have a broad personal network, built over two decades, from which to draw upon.   

While it is difficult to comment on the success of the strategy without comparable performance data it is clear Calculus is capable of raising and deploying capital effectively, with the EIS Fund alone attracting £184 million from investors.

Wealth Club aims to make it easier for experienced investors to find information on – and apply for – tax-efficient investments. You should base your investment decision on the provider's documents and ensure you have read and fully understand them before investing. This review is a marketing communication. It is not advice or a personal or research recommendation to buy the investment mentioned. It does not satisfy legal requirements promoting investment research independence and is thus not subject to prohibitions on dealing ahead of its dissemination.

The details

Target return
Funds raised / sought
Minimum investment
29 Oct 2021 for next tranche
Last updated: 20 April 2021

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