Restricted stock units (RSUs): what your shares cost you for Capital Gains Tax

Your cost for Capital Gains Tax on vested shares is their euro value at vesting, already taxed as pay. Older shares count as sold first.

When you sell shares that came from RSUs (restricted stock units), Capital Gains Tax (CGT) is charged on the gain over their cost. Getting the cost wrong is the most common way people overpay: RSU shares did not cost you nothing.

The cost is the value at vesting

You paid income tax, USC and PRSI on the market value of the shares on the day they vested. That value is your cost for CGT, so the same amount is not taxed twice. Revenue treats shares from an employee share purchase plan (ESPP) the same way. The cost for CGT is the full market value on the purchase date, not the discounted price you paid.

• Foreign shares: convert the vesting value to euro at the rate on the vesting date. Convert the sale proceeds at the rate on the sale date. Currency moves are part of your gain or loss.
• Sell to cover: shares sold at vesting to pay the tax are sold for about their cost, so there is little or no gain. They are still disposals; include them.
• Dealing costs on the sale reduce the gain.

Several vests: oldest shares are sold first

Shares of the same class bought on different dates are matched first in, first out (Revenue's shares page). If you hold shares from several vests and sell some, you are treated as selling the oldest first, whatever your broker shows.

Someone holds 100 shares that vested in March 2025 at $120 (a euro then bought $1.05). They hold 100 more that vested in March 2026 at $150 ($1.08). They sell 100 on 20 November 2026 at $185 ($1.10):

Using the newer shares' cost instead would have shown CGT of €514.38, €762.70 too little. That is the mistake to avoid.

The four-week rules

• Shares sold within four weeks of buying shares of the same kind are matched with those recent shares first (last in, first out). The oldest aren't used first.
• Say you sell at a loss and buy the same shares back within four weeks. Then the loss can only be used against a gain on the shares you bought back.

Records to keep

For each vest: date, number of shares, market value and exchange rate, usually on your employer's vesting statement or payslip. For each sale: date, shares, price, exchange rate and costs. Keep them for at least six years.

The shares from work calculator works out the cost, gain and CGT for each vest you sell, in euro.

Work it out

• Tax on shares from work: RSUs, options and ESPP →
• What the dollar does to your US shares →

Sources

• Revenue: Share awards and RSUs (taxed through PAYE; no employer PRSI on share-settled awards) (checked 20/10/2026)
• Revenue: How to calculate CGT (checked 25/10/2026)
• Revenue: Tax and Duty Manual Part 19-01-14a: gains computed by reference to the euro values of the purchase price and the sale proceeds (checked 16/10/2026)
• Irish Statute Book: Taxes Consolidation Act 1997, s.546(6): losses set against the highest-rate gains first (checked 20/10/2026)
• Revenue: eBrief No. 142/26: CGT standard rate reduced to 31% from 7 October 2026 (checked 25/10/2026)

General information, not tax advice. HeyPenny is not a tax agent.