Share Incentive Plan (SIP) Explained for UK Founders

Founders often grapple with a difficult question: how do you motivate your early employees when cash is scarce? Salaries alone rarely capture the sense of ownership that drives long‑term commitment. The share incentive plan (SIP) offers a way to share growth without draining the bank account. As one of the UK government's four approved employee incentive schemes, SIPs allow a company to grant or sell shares to employees while delivering significant income‑tax and National Insurance relief.

This guide breaks down the SIP for UK founders and directors in plain English. You'll learn what a share incentive plan is, how its four share types work, how SIP contributions operate, what happens when someone leaves, and how to set up a plan.

What is a Share Incentive Plan (SIP)?

A share incentive plan is a UK government‑approved company share scheme that allows employees to acquire shares in their employer tax‑efficiently. It was introduced by the Finance Act 2000 to encourage broad employee ownership. Unlike a management incentive plan used to reward senior executives, a SIP must be offered to all eligible employees on equal terms. Once employees join, their shares are held in a trust, often called a SIP trust or employee benefit trust (EBT), until they withdraw them or leave the company.

Here's the core idea in simple terms:

• Broad participation: All employees (UK residents) who meet any qualifying period must be invited to join. You can't run a SIP only for key hires.
• Trust‑based structure: Shares are held by independent trustees. The SIP Code requires the trust to be established under UK law and to be administered by UK‑resident trustees.
• Tax efficiency: Employees pay no income tax or National Insurance when they receive free shares, buy partnership shares from gross pay or reinvest dividends, provided the shares stay in the plan for the minimum holding period.
• Government approval: No HMRC approval is needed before launch, but the scheme must meet the requirements of Schedule 2 of the Income Tax (Earnings & Pensions) Act 2003 and must be registered via HMRC’s Employment Related Securities service.

By offering shares under a SIP, founders align employees’ interests with the company’s success, boost retention and potentially save the employer National Insurance contributions. In return, the scheme imposes rules: shares cannot be withdrawn before three years without forfeiting tax benefits, and leaver provisions must be clearly defined.

How does a SIP work? The four types of SIP shares

A share incentive plan can include up to four share types. Companies may choose one or a combination, tailoring the plan to their goals. Here's a breakdown of each type and the annual limits set by HMRC:

Most SIPs use free and partnership shares as the core. Matching shares boost employee uptake by effectively doubling the purchase, while dividend shares compound ownership without triggering tax. Employers may choose to offer only free shares or only partnership shares; the plan’s flexibility is one reason why share incentive plans are popular among large companies.

Example: Four share types in practice

Imagine an early‑stage fintech giving each employee £3,600 of free shares. An employee earning £40,000 decides to buy the maximum partnership shares: 10% of salary (£4,000), but the SIP rules cap contributions at £1,800. For each partnership share, the employer offers two matching shares. If the company shares are worth £10 each, the employee buys 180 partnership shares with their pre‑tax salary. The employer awards 360 matching shares and has already given 360 free shares. Dividends on these 900 shares can be reinvested to buy more shares. Because the partnership investment came from gross pay, the employee saved 28% in combined income tax and NI (20% basic rate plus 8% Class 1 NI) on the £1,800 contribution. After three to five years, those savings may compound significantly.

SIP contributions: How much can you put in?

Partnership share contributions are limited to the lower of £1,800 per year or 10% of salary. Employees can allocate monthly salary deductions or lump sums (for example, using a bonus). Because contributions are taken from gross pay, employees avoid income tax and National Insurance on that portion. For example, an employee contributing £1,800 from salary at a 20% tax rate and 8% National Insurance saves £504 in tax and NI. That means the shares effectively cost £1,296 while the employee owns £1,800 worth of equity.

• Free shares are limited to £3,600 per employee per year. Employers can link free shares to performance metrics, such as hitting product milestones or revenue targets, but all eligible employees must be offered the same performance conditions.
• Matching shares can be offered at up to two for one for each partnership share. Matching shares encourage participation because they multiply employees’ stake without additional cost. Employers choose the ratio and may impose forfeiture rules if employees withdraw partnership shares too early.
• Dividend shares allow participants to reinvest cash dividends into more shares. If the SIP rules permit, employees may choose or be required to reinvest dividends. Dividend shares must stay in the plan for three years for tax benefits.

A share incentive plan calculator helps founders model these limits and visualise tax savings. For instance, if you offer only partnership shares, plug in salary data to see how much employees can invest and the employer's National Insurance savings. Tools like Undo Capital’s cap table platform make these calculations easier by integrating share allocations with salary records and automatically generating legal documents.

The tax benefits of a Share Incentive Plan in the UK

Tax efficiency is the SIP’s main attraction. Here’s how the tax rules work:

1. Partnership shares purchased with pre‑tax salary are free from income tax and National Insurance at purchase.
2. Free shares, matching shares and dividend shares are awarded with no income tax or NI. However, employees must keep these shares in the plan for a minimum period.
3. Holding periods and tax relief:

This table shows why holding shares for at least five years maximises tax benefits. After five years, free, matching and partnership shares can be withdrawn tax‑free. Dividend shares only need to be held for three years to retain full relief.

4. Capital Gains Tax (CGT): If employees leave the SIP and sell shares, CGT may apply on any increase in value. However, if shares are transferred directly from a SIP into an Individual Savings Account (ISA) within 90 days of leaving the plan, the transfer is not treated as a CGT disposal. Any future gains on those shares inside the ISA are then sheltered from CGT entirely. Many companies encourage employees to move shares into an ISA to avoid capital gains.
5. Employer savings: Employers enjoy NIC savings because partnership contributions reduce salary. They can also claim corporation‑tax deductions for the cost of free and partnership shares and some setup costs. This dual benefit makes SIPs attractive to both sides.

Comparing SIP with EMI, CSOP and SAYE

The UK has four approved company share schemes: SIP, Save As You Earn (SAYE), Company Share Option Plan (CSOP) and Enterprise Management Incentives (EMI). SIP and SAYE are broad‑based plans offered to all employees, while EMI and CSOP are discretionary; you can select which employees receive options. The table below summarises the key differences:

For founders deciding between a SIP and other schemes, ask yourself: do you want every employee to own shares or just a handful of key people? If broad ownership is your goal and you’re prepared for the administrative work, a SIP offers generous tax benefits. If you need to target individual talent or are constrained by EMI eligibility limits, an EMI scheme or CSOP may be better. See our EMI scheme guide for details.

Who qualifies for a Share Incentive Plan?

A SIP must be offered to all employees on the same terms, but certain eligibility criteria apply:

• Employment status: Participants must be UK resident employees or directors. Consultants and contractors are excluded.
• Employer requirements: The company can be a listed company or an unlisted company. Private companies can set up a SIP via a trust structure; they are not required to be listed.
• Share requirements: Shares must be ordinary shares that are fully paid up and non‑redeemable, and they must be held in a UK‑resident SIP trust.
• Qualifying period: Employers may impose up to 18 months of service before employees can join. Performance conditions may also apply, but they must apply to everyone.

Because a SIP is an all‑employee incentive scheme, you cannot select only high earners or top performers. This differs from a management incentive plan, which is designed for a narrow group of senior staff. If your aim is to incentivise a small leadership team, consider alternatives like EMI or growth shares. For guidance on structuring your ownership records, see our cap table guide.

Share Incentive Plan: What happens when an employee leaves?

Leaver provisions are crucial in SIP design. When an employee leaves, their shares must come out of the plan. The treatment depends on the share type and the reason for leaving:

• Partnership shares always belong to the employee. They cannot be forfeited. However, if the employee withdraws them within three years, matching shares linked to them may be forfeited.
• Free shares and matching shares may be forfeited if the employee leaves within three years, unless they qualify as a good leaver. Common reasons include redundancy, injury, disability, change of control, retirement or death.
• Dividend shares follow the treatment of the underlying shares. If the employee sells partnership shares early, dividend shares linked to them may lose tax relief.

The HMRC manual defines a good leaver as someone leaving due to injury or disability, redundancy, certain transfers under the TUPE regulations, retirement or death. Good leavers do not pay income tax or NI on shares withdrawn from the SIP. Bad leavers, those resigning voluntarily or dismissed for misconduct, must pay income tax and NI if they withdraw shares within five years.

Clear leaver rules protect both employers and employees. They should be set out in the plan rules and communicated to participants. Undo Capital can help founders design leaver provisions that balance fairness with retention goals.

SIP vs Other UK share schemes: Which is right for you?

To decide whether a SIP is the right employee incentive scheme, consider these factors:

• Company size and goals: SIPs suit companies seeking broad employee ownership and that have the resources to administer a trust. HMRC statistics show adoption is modest; only larger companies typically run SIPs due to the administration cost.
• Selective vs all‑employee: If you want to reward specific individuals, a discretionary scheme like EMI or CSOP offers more flexibility. SIPs and SAYE schemes must invite all employees.
• Growth potential: EMI schemes provide large tax‑advantaged option grants, making them ideal for high‑growth startups. SIPs cap free shares at £3,600 per year, which might feel modest for senior executives but meaningful for broad staff.
• Funding stage: Early‑stage companies often operate lean. The cap table becomes complicated as you issue more equity. SIPs help align the team but require a trust structure. If resources are limited, simpler option plans might be easier.
• Administrative burden: Running a SIP means establishing a trust, holding shares in the trust, tracking contributions, reporting annually to HMRC and communicating with employees. Some founders outsource administration to providers like Undo Capital to reduce complexity.

How to set up a Share Incentive Plan in the UK (step‑by‑step)

Setting up a SIP requires careful planning. Here’s a practical step‑by‑step guide adapted from HMRC requirements and professional practice.

1. Check eligibility and obtain shareholder approval. Review your company’s Articles of Association to ensure you can issue shares and establish a trust. Private companies need board and shareholder consent to authorise SIP shares. Listed companies typically need formal shareholder approval.
2. Design the plan. Decide which of the four share types you will offer and set limits. Consider a qualifying period (up to 18 months of service) and performance criteria. Determine how many shares you will allocate and whether matching shares will be offered.
3. Establish the SIP trust. A Schedule 2 SIP must provide for a trust to hold plan shares. The trust deed must comply with HMRC requirements and be administered by UK‑resident trustees. You can appoint independent professional trustees or use a subsidiary company, but the trust must be separate from the company.
4. Prepare share valuations and agree with HMRC. Work with valuation experts to determine the fair value of the shares. You can submit a valuation request to HMRC's Shares and Assets Valuation team to agree the valuation in advance. Check the current form reference at gov.uk before submitting, as form numbers are subject to change. This step is not mandatory, but it gives certainty on tax treatment.
5. Draft plan rules and trust deed. Engage legal counsel to prepare the SIP rules and trust deed. These documents set out eligibility, share types, leaver provisions, holding periods and the rights attached to shares. The HMRC specimen rules provide a starting point, but your plan should reflect your company’s culture and goals.
6. Communicate the plan to employees. Effective communication is vital. Explain how partnership shares reduce taxable pay, highlight holding periods, and spell out leaver rules. Use clear language and include examples. Tools like Undo Capital’s equity platform can provide automated communications and employee dashboards.
7. Register and self‑certify the plan with HMRC. You must register the SIP via HMRC’s Employment Related Securities service and self‑certify it by 6 July following the tax year in which shares are first awarded.
8. Administer the plan on an ongoing basis. After launch, track contributions, share allocations and holding periods. File an annual return by 6 July each year. Maintain records of share movements and monitor compliance. Consider using dedicated software or an administrator to simplify this process.

By following these steps and seeking professional advice, you can establish a SIP that meets HMRC requirements, engages your team and avoids compliance risks.