Is an Irish UCITS always better than a US-domiciled ETF?

No. The withholding saving scales with the fund's dividend yield, while the higher expense ratio a UCITS wrapper usually carries is charged against the entire position. On a broad dividend-paying fund held by an investor with no US treaty the switch is usually clearly worth it; on a low-yield fund, or for a resident whose treaty rate is already 15% or lower, it can be net negative.

How do I work out whether to switch to a UCITS fund?

Compare two annual costs rather than one. First, withholding: position value times dividend yield times the rate that applies to your residence, against 15% suffered inside an Irish UCITS at fund level. Second, the expense ratio on the whole position for each fund. The switch is worth it only where the withholding saved exceeds the extra expense ratio, and there is a dividend yield at which the two are exactly equal.

Why does fund domicile change dividend withholding at all?

An Irish-domiciled UCITS holding US stocks pays 15% US tax at fund level under the US–Ireland treaty, and Ireland applies no further withholding to non-resident investors. A US-domiciled fund instead withholds from the distribution paid to you, at your own treaty rate or at the 30% statutory rate. The two routes can leak different amounts on the same underlying index.

BorderFolio/Withholding by residence/UCITS vs US-domiciled

UCITS vs US-domiciled: both sides of the switch

Withholding rates from IRS Table 1 (Rev. May 2023) · last reviewed 31 August 2026

"Non-US investors should hold Irish UCITS" is the most repeated piece of cross-border advice there is, and it is right often enough to sound universal. It isn't, because it counts one side of a two-sided sum. The tax saving scales with dividend yield. The extra expense ratio is charged on your whole balance. Different denominators, and which one wins depends on numbers only you have.

Position (USD)

Yield (%)

US TER (%)

UCITS TER (%)

Residence

This calculator needs JavaScript. The rate for every residence is listed on the country table.

Why there is no ticker lookup here

The obvious version of this tool takes a ticker and hands back "the Irish equivalent." I decided against building that, for two reasons worth stating plainly.

The first is that "equivalent" is a judgement, not a fact. Two funds tracking related indices can differ in index methodology, share class, currency hedging, securities lending policy, spread and tracking difference. A lookup table flattens all of that into an equals sign it hasn't earned.

The second is that naming a replacement fund is a recommendation, whatever disclaimer sits under it. This site doesn't make those. What it can do is give you the arithmetic, both sides of it, on the two funds you have already chosen to compare — which is the part that is genuinely missing everywhere else.

Expense ratios come from each fund's own factsheet or KID. Yield is on the same document, or on your own statement, which is better because it is what the fund actually paid you rather than what it advertises.

What the comparison leaves out

The cost of switching itself. Selling to switch can realise a taxable gain, and that one-off cost is frequently larger than several years of the annual difference computed above.
Tax in your country of residence. Only the withholding step is modelled. An accumulating UCITS also changes when you are taxed at home, which for some residences matters more than the rate.
Tracking difference, spread and lending revenue, which can move the real gap by more than a few basis points of stated TER.
Interest-type distributions. Treasury and money-market payouts are exempt rather than taxed at the dividend rate, so applying a withholding rate to them overstates the leak.
Whether you can buy either fund at all. A documentation rule blocks many US-domiciled ETFs for retail investors in the EU regardless of what the arithmetic says.

Dividend withholding calculatorWhat the US takes before the dividend reaches you. US estate tax calculatorThe $60,000 line, and what sits above it. Withholding methodologyThe two-step model in full, and what the estimate cannot see. Investment & tax disclaimerThe formal statement of what BorderFolio is and is not.

Run this per holding, automatically Informational estimates only — not financial, investment, legal or tax advice.