Tax Last Fact-Checked: 19 April 2026 · 5 min read

The Ireland–US Tax Treaty and What It Means for Your S&P 500 ETF

Why you should own CSPX or SPPW rather than SPY or VOO — and how the 15% withholding tax rate for Irish-domiciled funds adds up to real money over time.

Not financial advice. The information on etf.ie is for educational purposes only and does not constitute financial, tax, or investment advice. ETF investing involves risk, including the possible loss of capital. Tax rules may change — always verify current Revenue guidance and consult a qualified financial adviser or tax professional before making investment decisions.

April 2026 Note: While the Exit Tax rate was reduced to 38% in the Finance Act 2025, the 8-year Deemed Disposal mechanism and overall funds tax regime remains in place and under review by the Department of Finance.

Why Irish investors can't buy SPY or VOO

The S&P 500 index funds most widely known internationally — Vanguard's VOO and VTI, State Street's SPY, iShares' IVV — are listed in the United States and cannot be sold to retail investors in Ireland or the EU. This is not an obscure technicality; it's a hard legal restriction under the EU's PRIIPs regulation (Packaged Retail and Insurance-based Investment Products), which requires any fund marketed to EU retail investors to publish a standardised Key Information Document (KID).

US-listed ETFs don't publish EU KIDs — they have no obligation to. Your broker will typically block the purchase attempt. Even if you found a workaround, there's a more fundamental reason to avoid US-listed ETFs as an Irish investor: the dividend withholding tax.

The dividend withholding tax story

S&P 500 companies pay dividends. When a fund holds US stocks, the IRS withholds a portion of dividends before they reach the fund. How much depends on where the fund is domiciled:

Fund domicile Tax treaty with US? WHT rate on US dividends Examples
Ireland (IE) Yes — 15% 15% CSPX, SPPW, VWCE, IWDA
Luxembourg (LU) Partial — 15–30% 15–30% Some LU-domiciled funds
No treaty jurisdiction No 30%
US-listed (SPY, VOO) N/A — different regime 30% WHT for Irish resident individuals SPY, VOO, VTI, IVV

Ireland's double taxation agreement with the United States allows Irish-domiciled funds to receive US dividends with only 15% withheld at source. This compares favourably with the 30% default rate that applies to entities in non-treaty jurisdictions.

The S&P 500 currently yields approximately 1.3–1.5% per year in dividends. On a €100,000 portfolio, that's roughly €1,400/year in dividends. The difference between 15% and 30% withholding on that amount is €210/year — compounded over 20–30 years, this is meaningful.

CSPX vs SPPW — which S&P 500 ETF for Irish investors?

For Irish investors who want S&P 500 exposure, the two main UCITS options are:

CSPX
iShares Core S&P 500 UCITS ETF
IE00B5BMR087 · TER 0.07% · Distributing
  • • Distributes dividends quarterly
  • • USD denominated on LSE (GBP also available)
  • • One of the largest UCITS ETFs by AUM
  • • Available on DEGIRO (core list)
SPPW
SPDR S&P 500 UCITS ETF (Acc)
IE00BYML9W36 · TER 0.03% · Accumulating
  • • Reinvests dividends automatically
  • • Cheapest S&P 500 UCITS ETF by TER
  • • EUR share class available
  • • Generally preferred for Irish tax efficiency
For Irish investors, SPPW (accumulating) is generally preferable. As a distributing fund, CSPX pays out dividends — which become a taxable income event for Irish resident investors each quarter. SPPW reinvests dividends internally (the 15% WHT is still paid at the fund level, but there's no additional Irish income tax event). For long-term accumulators, avoiding quarterly dividend income events simplifies administration and avoids the need to reinvest small cash payments manually.

How the WHT difference compounds over time

Assume you invest €100,000 in an S&P 500 ETF with a 7% gross return and 1.4% dividend yield. The impact of 15% vs 30% dividend withholding over 20 years (ignoring Irish exit tax for illustration purposes):

Year Irish-domiciled ETF (15% WHT) 30% WHT fund Difference
5 years €138,500 €137,700 €800
10 years €191,900 €189,700 €2,200
20 years €368,100 €360,200 €7,900
30 years €706,200 €683,700 €22,500

Illustrative only. Assumes 7% gross annual return, 1.4% dividend yield, 15% vs 30% WHT on dividends. Accumulating fund, no distributions. Pre-exit-tax.

Over 30 years, the WHT advantage of an Irish-domiciled fund amounts to roughly €22,500 on a €100,000 starting investment — purely from the treaty benefit. For a larger portfolio, the absolute gain scales proportionally.

How to verify a fund is Ireland-domiciled

The simplest check: look at the ISIN. ISINs beginning with IE are Irish-domiciled. ISINs beginning with LU are Luxembourg-domiciled. Both are UCITS funds and both offer the 15% WHT benefit on US dividends under their respective tax treaties.

The domicile is also stated on the ETF's Key Information Document (KID) or fund factsheet, available on the provider's website (iShares.com, Vanguard.ie, SPDR ETFs).

Quick reference — ISIN prefixes:
IE00... — Ireland-domiciled (15% US WHT)
LU00... — Luxembourg-domiciled (varies, often 15%)
US00... — US-listed (not available to EU retail investors; adverse WHT for Irish individuals)

What about global ETFs like VWCE?

The same logic applies to global ETFs. VWCE is Ireland-domiciled (IE00BK5BQT80) and benefits from the 15% WHT treaty rate on its US holdings. Since the US represents approximately 64% of the FTSE All-World index, the WHT treaty benefit is significant even for a global fund.

This is one reason why Irish-domiciled UCITS ETFs are generally considered the optimal structure for global equity exposure — the combination of Ireland's extensive treaty network, the UCITS regulatory framework, and the 15% US WHT rate makes them difficult to beat from a tax efficiency standpoint.

Not financial advice. The information on etf.ie is for educational purposes only and does not constitute financial, tax, or investment advice. ETF investing involves risk, including the possible loss of capital. Tax rules may change — always verify current Revenue guidance and consult a qualified financial adviser or tax professional before making investment decisions.