IB01 is an Ireland-domiciled UCITS fund that is generally a PFIC for US persons. The iShares plc prospectus names this fund and makes no provision for a PFIC Annual Information Statement, which a QEF election needs for each year — so unless BlackRock (iShares) supplies one, the routes left are mark-to-market (if the listing qualifies) or the §1291 default.
Source: iShares plc prospectus, checked .
As an accumulating share class, it reinvests income rather than paying it out. A later sale can still trigger §1291 tax and interest; the outcome depends on your holding period, transactions and election history.
By Danilson Ramos · Founder, Atamatax
Fund facts verified against issuer sources ·
No card · free draft · professional per-form preparation starts at $170 per Form 8621 (Bright!Tax’s published floor, no distributions); the PFIC package is a flat $499 for up to 25 Forms 8621, which you review and file.
If IB01 is confirmed as a PFIC, you may need a separate Form 8621. For supported inputs the paid package gives a Form 8621 for each supported PFIC — a pre-filled official PDF only for a tax year whose official form is integrated and released, otherwise a worksheet with every figure mapped to the form's lines; review its notes and complete any remaining fields before filing outside Atamatax.
IB01 pays out nothing, so there may be no cash distribution to enter in a §1291 excess-distribution calculation while you hold. Separate annual Form 8621 reporting can still apply.
Mark-to-market (§1296) taxes the annual paper gain as ordinary income — and an accumulating fund sends you no cash to pay it with. Worth planning before you elect.
IB01 tracks ultra-short US Treasury bills through an Irish fund vehicle. It is where people park money they consider uninvested, which is why it gets missed. A conventional foreign short-duration fund typically earns passive interest and commonly meets §1297; confirm the vehicle and Form 8621 reporting obligation rather than treating cash-like exposure as automatically exempt.
A cash-parking position is usually the cheapest PFIC in a portfolio to actually report, because gains are small and the holding period is short. Leaving it off the return is a much more expensive mistake than including it.
IB01 pays you nothing. The money-market style interest are reinvested inside the fund instead of hitting your account. Under the default §1291 rules, there may be no cash distribution to test as an excess distribution while you simply hold, while a later disposition can still trigger the allocation and interest-charge regime. Separate annual Form 8621 reporting can also apply during the holding period.
A sale at a gain can still create a substantial bill. Under §1291, the gain is allocated across the holding period: current-year and pre-PFIC amounts are ordinary income, while earlier PFIC-year amounts use the highest applicable tax rate for each year and can carry interest. That interest runs between the relevant return due dates without extensions. Accumulation alone does not establish which share class produces the larger tax bill.
One knock-on worth planning around: a mark-to-market election under §1296 taxes the annual paper gain as ordinary income — but IB01 distributes no cash, so that tax has to be funded from somewhere else every year.
IB01 is the iShares $ Treasury Bond 0-1yr UCITS ETF (Accumulating), ISIN IE00BGSF1X88. Match the ticker — and the ISIN, where your statement shows one — to this line before reading the mechanics above as yours.
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A routing read, not a determination. Whether a fund is a PFIC, whether an exception applies and what a prior year needs are established when the holdings are screened; the route above says where that happens and what it costs.
This is a screening assessment based on published vehicle facts and the statutory tests—not a classification based on domicile alone, and not individualized tax, legal, or investment advice — see our methodology (IRC §1297 et seq.). Confirm your specific situation with a licensed professional.
Primary sources (Cornell Legal Information Institute for the US Code and CFR; IRS.gov for forms, procedures, and treaty documents). This page is general information, not individualized tax or legal advice.
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