Form 8288-B Withholding Certificate: UK Sellers' Guide

A Form 8288-B withholding certificate is the IRS application a foreign seller files to reduce or eliminate the 15% FIRPTA withholding on a US property sale. It replaces withholding on the gross price with withholding based on the actual expected tax, so the cash stays with you rather than sitting at the IRS for a year or more.

What a Form 8288-B withholding certificate actually does

The Foreign Investment in Real Property Tax Act (FIRPTA) does not tax the buyer, but it makes the buyer responsible for collecting tax from you. On the disposition of a US real property interest by a foreign person, the transferee must generally withhold 15% of the amount realised and remit it to the IRS. The critical word is "realised". Withholding is calculated on the gross consideration, not on your profit, not on your net proceeds, and not after the mortgage is repaid. Where a liability is assumed by the buyer, that too forms part of the amount realised.

For a UK-resident seller of a long-held US property, this produces a routinely absurd result: 15% of a $2.4m sale price is $360,000, while the federal tax genuinely due on the gain might be $130,000. The difference is not lost, but it is gone — held by the IRS until you file a US return for the year of sale and wait out the refund cycle. On a large disposition that is a seven-figure timing problem, and it frequently collides with a UK reinvestment, a completion elsewhere, or a distribution to family.

Form 8288-B is the remedy. It asks the IRS, in advance, to certify that a smaller amount (or nothing at all) need be withheld, because the maximum tax that could arise on the transaction is demonstrably lower than 15% of the price. The IRS publishes the form and its instructions on About Form 8288-B, and sets out the categories of application and the review process on its withholding certificates page.

This is the seller's filing, not a buyer-side structure

It is worth being explicit, because the two subjects are constantly conflated. Choosing how to acquire US real estate — personally, through an LLC, a US blocker corporation, a foreign corporation, or a trust — is an entry-point decision that determines your exposure to US estate tax, the rate on rental income, and how FIRPTA will bite on a future exit. We deal with that separately in our guide to FIRPTA and structuring for non-US investors buying US real estate.

Form 8288-B is the opposite end of the timeline. The property is already owned, the structure is already fixed, and a buyer is already at the table. Nothing about the 8288-B changes your tax liability by a single dollar. It changes only how much cash is intercepted at completion. Anyone who tells you that a withholding certificate reduces your US tax has misunderstood the mechanism. It is a compliance filing that restores your liquidity, and it is judged on the quality of the evidence you put in front of the IRS, not on advocacy.

How much is withheld if you do nothing?

The statutory default is 15% of the amount realised, but there are two exceptions worth knowing before you conclude an application is necessary. Both depend on the buyer's intentions, not yours, which means they are only usable when the buyer will cooperate and certify.

Scenario	Withholding on amount realised	Practical note for a UK seller
Standard disposition by a foreign person	15%	Applies to most HNW dispositions; calculated on gross price
Buyer acquires as a residence, price $300,000 or less	Nil	Buyer must certify a defined residence-use intention; rare at our client sizes
Buyer acquires as a residence, price above $300,000 and not more than $1,000,000	10%	Useful on smaller city apartments; still gross-based
Certificate obtained on Form 8288-B	As certified by the IRS, potentially nil	Based on maximum tax liability, evidenced
Seller is in fact a US person	Nil (FIRPTA does not apply)	Certified on Form W-9, not Form 8288-B

The IRS summarises the rates and the residence exceptions on its FIRPTA withholding page. Note that the residence exceptions turn on the buyer's plans to occupy the property, and a buyer's attorney will not certify casually. Do not build a completion timetable around an exception the buyer has not yet agreed to sign for.

When is a withholding certificate worth the effort?

The test is arithmetic. Compare 15% of the price with the federal tax genuinely expected on the gain. Where the property has been held for many years and appreciated strongly, the two numbers can be close and an application adds little. Where the property was bought near the top of a cycle, refinanced, heavily improved, or is being sold at a modest gain, the gap is enormous.

A worked comparison

Take a UK-resident, non-US-citizen client selling a Florida house for $2,400,000. Original cost $1,650,000. Capital improvements of $180,000. Depreciation allowed or allowable during a rental period of $210,000, giving an adjusted basis of $1,620,000. Selling costs of $144,000.

• Amount realised for FIRPTA: $2,400,000. Default withholding at 15%: $360,000.
• Gain: $2,400,000 less $144,000 selling costs less $1,620,000 adjusted basis = $636,000.
• Unrecaptured section 1250 gain of $210,000 taxed at up to 25%: approximately $52,500.
• Remaining long-term gain of $426,000 at 20%: approximately $85,200.
• Indicative federal tax: approximately $137,700.

Roughly $222,000 of the seller's own money would otherwise sit with the IRS for the better part of a year. That is the number a certificate is designed to release. Note also that as a non-resident alien the seller is outside the 3.8% net investment income tax, which flatters the comparison relative to a US-citizen seller — a distinction that matters enormously if it turns out the client is a US person after all.

What the application has to prove

Most applications by UK sellers proceed on the basis that the maximum tax that could be imposed on the disposition is less than the tax otherwise required to be withheld. That is an evidential claim, and the IRS reviews it as one. A thin application is not refused on principle; it is refused, or parked, for want of documents.

The gain computation

You are effectively filing a pro-forma calculation of the disposition a year before the return that will report it. It must be internally consistent with the return you will eventually file, and it must reconcile to the closing documents. Expect to supply the original purchase settlement statement, the draft settlement statement for the pending sale, invoices or a schedule substantiating capital improvements, and — if the property was ever let — the depreciation schedules.

The depreciation trap

Basis is reduced by depreciation "allowed or allowable". If the property was rented and depreciation was never claimed because no US return was ever filed, the basis is still reduced. This surprises UK owners constantly. It produces a larger gain than the client expects, a larger maximum tax liability, and a smaller reduction than hoped — and it exposes the underlying problem, which is unfiled US returns for the rental years.

Prior US compliance

An application that reveals years of unreported US-source rental income is an application in difficulty. Where a UK owner has let a US property for a decade without filing Form 1040-NR, the sensible sequence is to remediate the filing history first, or at minimum to run the remediation in parallel and disclose it. Our IRS streamlined filing team handles that alongside the disposition, and it is far better to arrive at the IRS with a coherent history than to have a certificate application be the thing that opens the file.

The ITIN problem

Every foreign transferor on the application needs a US taxpayer identification number, and the IRS will not act on an application without the TINs of the parties. A UK seller who has never filed a US return will not have an ITIN, and cannot obtain one purely in anticipation. In practice the Form W-7 application runs with the 8288-B, supported by the executed contract. Certified copies of the passport, or the use of a Certifying Acceptance Agent, avoid sending an original passport to Austin — a point that matters when the client also needs to travel.

Timing the application against completion

This is where transactions come unstuck, and where the internet is most misleading. Two separate deadlines operate, and only one of them is about the IRS.

The hard deadline: on or before the date of transfer

The application must be filed no later than the date of the transfer. An application submitted after completion does not protect the funds; by then the withholding obligation has crystallised and the money is on its way to Ogden. Practically, we want the application in the IRS's hands well before exchange, and certainly not in the final week of a transaction.

The soft deadline: the IRS's 90 days

The IRS states that it will normally act on a complete application within 90 days of receiving everything it needs, including the TINs of all parties. Read that carefully. The clock runs from completeness, not from posting, and an application waiting on an ITIN is not complete. A request for further information restarts your practical timetable. Ninety days is a target, not a guarantee, and applications filed in the busiest parts of the US filing season are slower.

The notification the seller must give the buyer

A transferor who applies for a withholding certificate must notify the transferee in writing that the certificate has been applied for, on the day of or the day before the transfer. This is a small formality that closing attorneys and title companies rely on, and forgetting it can cause a nervous withholding agent to remit anyway. Name the escrow or closing agent on the application so the IRS's determination reaches the people holding the money.

What happens to the money while the IRS decides?

A widely repeated misconception is that a pending application suspends withholding. It does not. The withholding obligation still arises at transfer, and the buyer or closing agent must still withhold the full amount. What changes is the remittance: where an application is pending on the date of transfer, the withheld amount is not required to be reported and paid over until the 20th day following the IRS's final determination on the application.

In practice the funds sit in escrow, and the closing agent needs written comfort — and often an indemnity — before agreeing to hold rather than remit. Some title companies will not hold at all as a matter of policy, in which case the money goes to the IRS on the ordinary timetable and the certificate becomes a refund exercise instead of a cash-flow one. Establish the escrow agent's policy before you commit to a completion date, not after.

• Certificate approved: the closing agent releases the excess to the seller and remits only the certified amount, with Forms 8288 and 8288-A filed within 20 days of the determination.
• Certificate approved in part: the same, at the reduced figure the IRS specifies rather than the figure you asked for.
• Certificate denied: the full 15% is remitted, and the excess is recovered only through the US return for the year of sale.

The Form 1040-NR that still has to follow

A withholding certificate is not a settlement of your US tax, and it is not a substitute for a return. Whatever the IRS certifies, a non-resident individual who disposes of a US real property interest must file Form 1040-NR for the year of the disposition, report the gain, compute the actual tax, and claim credit for the amount withheld. The certificate simply means the credit and the liability are close to each other rather than wildly apart.

Three points regularly catch UK sellers out. First, the credit is evidenced by the stamped Copy B of Form 8288-A; if you never receive one because the withholding agent filed incorrectly, you must be ready to substantiate the withholding by other means. Second, the filing deadline for a non-resident alien without US wages subject to withholding falls later in the year than the familiar April date, and an extension can push it later still — but an extension to file is not an extension to pay. Third, where the disposition is the only US-connected event, this is often the client's first US return, and it needs to be consistent with the pro-forma numbers used on the 8288-B. Our US tax services team prepares the two as a single piece of work for exactly that reason.

Refunds of over-withheld FIRPTA tax are notoriously slow. That is not a reason to skip the return; it is the argument for the certificate.

State withholding sits on top of FIRPTA

Federal withholding is only part of the intercept. Several states operate their own non-resident real property withholding regimes with their own forms, thresholds and waiver applications, and they are entirely separate from Form 8288-B. California, Hawaii, Maryland, New York and others each run distinct systems; Florida and Texas, having no personal income tax, do not. A certificate from the IRS does nothing at all about a state deduction, and a state waiver has its own timetable that must be run in parallel. On a nine-figure portfolio disposition across several states, this is a project-managed exercise rather than a form.

The UK side: what HMRC does with all of this

For a UK-resident individual taxed on the arising basis, the same disposal is a chargeable gain for UK capital gains tax. The US-UK double tax treaty allocates primary taxing rights over gains on immovable property to the country where the property sits, and the UK relieves the double charge by credit. The mechanics are unforgiving in ways that surprise people.

Issue	United States (IRS)	United Kingdom (HMRC)
What is taxed	Gain on the US real property interest, long-term rates plus unrecaptured section 1250 gain	Chargeable gain on the same disposal, computed under UK rules
Currency	US dollars throughout	Sterling: cost converted at the acquisition-date rate, proceeds at the disposal-date rate
Depreciation	Reduces basis whether or not claimed; recaptured on sale	No equivalent reduction to base cost for a residential let
Tax year	Calendar year	6 April to 5 April
Headline rate on the gain	Typically 20% plus 25% on unrecaptured section 1250 gain; no 3.8% NIIT for non-resident aliens	24% for higher and additional rate taxpayers from 6 April 2026
Relief for the other country's tax	Not applicable; the US taxes first	Foreign Tax Credit Relief for the US tax properly due

HMRC credits the tax, not the withholding

This is the single most important cross-border point on this page, and generalist articles miss it entirely. Foreign Tax Credit Relief is given for foreign tax properly payable, not for the amount an agent happened to deduct. If $360,000 is withheld and your actual US liability is $137,700, HMRC will relieve by reference to the latter. The over-withheld $222,300 is not a UK credit; it is a US receivable. Claiming relief for the withheld figure produces an incorrect return and an assessment when the position unwinds. HMRC's overview of relief where you are taxed twice makes the point that relief can be less than the foreign tax paid, and the credit is in any event capped at the UK tax on the same gain.

The sterling gain is a different number

UK capital gains are computed in sterling by converting cost at the rate on acquisition and proceeds at the rate on disposal. A property bought when sterling was strong and sold when it is weak can produce a substantial sterling gain out of a modest dollar gain — or, less often, the reverse. UK tax can therefore exceed the US tax on the identical transaction, leaving unrelieved UK exposure that no 8288-B can help with. Model both currencies before you agree a price, not after. Current UK rates and the annual exempt amount are set out on the GOV.UK capital gains tax rates page.

The tax years do not line up

A December completion is a US 2026 event and a UK 2026/27 event. A March completion is a US 2027 event and a UK 2026/27 event. Because credit relief generally depends on the foreign tax being paid or payable on the same income or gain, the sequencing of the US return, the certificate and the UK self assessment needs deliberate planning. For clients who have recently arrived in the UK, the four-year foreign income and gains regime may take the gain outside UK charge altogether — in which case the US position is the only position, and getting the withholding right is the whole game. We handle that interaction as part of cross-border tax planning and for larger estates through our high net worth practice.

Where Form 8288-B applications go wrong

• Filed too late. Submitted after completion, when the money has already gone.
• Incomplete on arrival. No ITIN, no signed contract, no settlement statement, so the 90-day clock never starts.
• Ignored depreciation. A gain computation that omits allowable depreciation is inconsistent with the return that follows and invites scrutiny.
• No escrow agreement. The certificate arrives after the closing agent has already remitted, converting a cash-flow win into a refund claim.
• Joint owners treated as one. Spouses or co-owners each have their own foreign-person status, their own TIN requirement, and their own share of the gain.
• Unfiled rental years left undisclosed. The fastest route from a routine certificate to an examination.
• Assuming the treaty helps. It does not exempt you from FIRPTA withholding, and there is no treaty article that turns it off.

What if the seller turns out to be a US person?

We see this several times a year. A client who has lived in London since childhood, holds a US passport by birth or descent, and considers themselves entirely British is not a foreign person for FIRPTA. No withholding is required, and no Form 8288-B is appropriate; the correct document is a Form W-9 certification of non-foreign status. But the relief is superficial, because a US person has a worldwide filing obligation that has probably been unmet for years, and a property sale is a highly visible event to be discovered on. The right response is a controlled disclosure through the Streamlined Foreign Offshore Procedures before completion, not a certificate application that misstates the seller's status. If there is any doubt about citizenship or long-term residence history, resolve it first — our private client tax team starts every FIRPTA engagement with that question.

How Jungle Tax runs a FIRPTA disposition

We prepare the Form 8288-B, the supporting gain computation and the ITIN applications; we liaise directly with the closing agent and the buyer's attorney about escrow and the written notification; we track the IRS determination; and we prepare the Form 1040-NR that follows, reconciled to the numbers we filed months earlier. Where the UK return is also ours, the Foreign Tax Credit Relief claim is built from the actual US liability rather than the withheld figure, in the correct sterling amounts. It is one piece of work with two tax authorities, and it goes wrong when it is split between advisers who each see half of it.

If you are contemplating a US property sale from the UK, the useful moment to speak to us is before you accept an offer — not after a closing agent has told you what will be deducted. Contact our cross-border team for a confidential consultation on your disposition, the certificate application, and the US and UK returns that follow.