Share Incentive Plans (SIP): The 5-Year Rule That Makes Them Fully Tax-Free
A Share Incentive Plan lets employees hold company shares free of income tax and NI if kept for 5 years. Leave early, and a sliding scale of tax kicks back in. Here is the full 2026/27 breakdown.
The Four Types of SIP Shares
A Share Incentive Plan is an HMRC tax-advantaged scheme that can combine up to four types of shares, held within a UK-resident trust on the employee's behalf:
| Share type | How it works |
|---|---|
| Free Shares | Given by the employer at no cost to the employee, up to £3,600 worth per tax year |
| Partnership Shares | Bought by the employee from pre-tax, pre-NI salary, up to £1,800 per tax year or 10% of salary (whichever is lower) |
| Matching Shares | Given free by the employer, matched to Partnership Shares purchased — commonly at a ratio up to 2 Matching Shares per 1 Partnership Share |
| Dividend Shares | Dividends paid on SIP shares reinvested into further shares within the plan, rather than paid out as cash |
Not every employer offers all four types — many SIPs focus on Partnership and Matching Shares as the core structure.
The 5-Year Full Exemption
The central tax advantage of a SIP is this: shares held within the plan trust for at least 5 years from their award date can be removed entirely free of income tax and National Insurance, regardless of how much their value has grown.
Additionally, because the capital gains tax "base cost" for shares removed from a SIP is set at their market value on the date of removal (not the original award value), selling immediately on removal after 5 years also generally avoids any capital gains tax on the growth that occurred while the shares were held in the plan — a genuinely powerful combined tax benefit.
The Sliding Scale for Early Removal
| Time held before removal | Tax treatment |
|---|---|
| Less than 3 years | Income tax and NI due on the full market value at date of removal |
| 3 to 5 years | Income tax and NI due on the lower of (a) market value at date of award, or (b) market value at date of removal |
| 5 years or more | No income tax or NI due at all |
This structure means leaving before 3 years is the most costly outcome, since the full current market value (which may have grown considerably) is taxed. Between 3 and 5 years, using the lower of the award-date or removal-date value provides some protection against paying tax on growth achieved during a shorter holding period, but it's still meaningfully less favourable than waiting the full 5 years.
Worked Example: Partnership + Matching Shares
| Element | Detail |
|---|---|
| Employee salary | £40,000 |
| Partnership Shares bought (10% of salary, within £1,800 cap check) | £1,800/year (below the 10% of salary limit) |
| Matching Shares from employer (1:1 ratio in this example) | £1,800/year |
| Total shares acquired per year (before growth) | £3,600 worth |
| Income tax/NI saved on Partnership Share purchase (basic rate, 20% + 8% NI) | £504 (28% of £1,800) |
Beyond the immediate tax/NI saving on the Partnership Share purchase itself, the employee also receives an equivalent value in free Matching Shares from the employer — and if all shares are held for 5 years, the entire combined value (plus any growth) comes out free of income tax and NI.
SIP vs Other Employee Share Schemes
| Scheme | Key feature |
|---|---|
| SIP | Actual shares held in trust; 5-year full exemption; includes Partnership Shares bought from pre-tax salary |
| SAYE (Sharesave) | Savings-linked option scheme; save monthly, option to buy shares at a discount set at the start |
| EMI (Enterprise Management Incentives) | Share options for smaller, higher-growth companies; can offer very favourable CGT treatment (including potential BADR eligibility) on exercise |
| CSOP (Company Share Option Plan) | Discretionary share options with statutory limits, available more broadly than EMI |
SIPs are distinctive in that employees hold actual shares (not just options) from an early stage, and the pre-tax salary purchase mechanism for Partnership Shares gives an immediate saving that other schemes don't replicate in quite the same way.
What Happens When You Leave Your Job
If you leave your employer before the 5-year holding period completes, your SIP shares generally must be removed from the plan, triggering the sliding-scale tax treatment described above based on how long you'd held them at that point.
Some schemes provide more favourable treatment for "good leavers" — commonly defined to include redundancy, retirement, injury, disability, or death — though the specific provisions vary by employer's scheme rules, so it's worth checking your own plan documentation (or asking HR) rather than assuming a universal standard applies.
Practical Tips
- If you're close to the 5-year mark and considering leaving your job, understand the potential tax cost of forfeiting the full exemption before making a final decision, where the timing is within your control.
- Contribute to Partnership Shares up to the annual limit if you can afford to, given the immediate tax/NI saving, but be mindful this reduces your take-home pay in the short term.
- Check whether your employer offers Matching Shares and at what ratio — a generous match significantly increases the overall value of participating.
- Understand your specific scheme's leaver provisions before assuming standard tax treatment will apply if your employment ends unexpectedly.
Frequently asked questions
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