What good is a warning that never tells you the number?
Starting January 1, 2027, anyone selling or buying a piece of enrolled farmland in Loudoun County will hit a new form at the settlement table. A law passed by the General Assembly this year requires it. But read the law closely enough and a strange thing becomes clear: it guarantees that someone will hand you a warning. It does not guarantee that anyone will hand you a figure. For sellers and buyers of horse farms and rural acreage in western Loudoun, that gap between being warned and being informed is the part worth understanding now, months before the law takes effect.
The Story Everyone Already Half-Knows
Loudoun County, like most Virginia localities, lets qualifying agricultural, horticultural, forestry, or open space land get taxed on what it earns rather than what it would sell for. A hayfield taxed as a hayfield instead of as future subdivision lots can carry a real estate tax bill a fraction of its market-value equivalent. The program has existed in Loudoun since 1973, and it is exactly the kind of tax relief a working horse farm or a pastured acreage parcel is built to use.
The tradeoff has always been the rollback. Change the qualifying use, subdivide the parcel, or rezone to something more intensive, and the county collects the difference between what you paid and what you would have paid at full market value, going back several years. Most owners who have held enrolled land for a while know this exists in the abstract. Fewer know exactly what it costs, and even fewer know that starting this winter, someone else is legally obligated to raise the subject before closing.
What the Rollback Actually Adds Up To
Loudoun's ordinance sets the rollback at the difference between the fair market value tax and the use value tax for the five most recent complete tax years, plus the current year at full market value, plus simple interest at five-sixths of one percent per month. Do the arithmetic and that interest rate comes out to an even 10 percent a year, simple rather than compounding, which matters because simple interest on a five-year liability is meaningfully cheaper than compounded interest would be over the same stretch.
Five years is the baseline. It is not always the ceiling. Loudoun also offers a sliding scale option, where an owner commits in writing to keep land in its qualifying use for longer than five years in exchange for a deeper tax deferral. The tradeoff is that if the use changes anyway, the county reaches back to the effective date of that agreement, not just five years. Loudoun's own guidance walks through the math with a specific example:
| Sliding scale enrolled | Use changes | Rollback years owed |
|---|---|---|
| 2015 | 2019 | 2019, plus 2014 through 2018 (5 years) |
| 2015 | 2023 | 2023, plus 2015 through 2022 (8 years) |
The longer an owner stays enrolled under a sliding scale commitment, the larger the exposed window gets if that commitment ever breaks. A farm that looks like a routine five-year rollback on paper can turn into an eight-year one depending on when the sliding scale agreement was signed, and that detail lives in county records, not in the assessed value shown on a listing sheet.
Scale also matters here in a way easy to miss. As of January 2025, Loudoun County's own budget documentation put the total value enrolled in the land use program at approximately $833.9 million, under half a percent of the county's taxable real property. Countywide, that sounds like a rounding error. It is not evenly distributed. That deferred value sits almost entirely in the rural west, on exactly the kind of acreage a horse farm buyer is looking at. A parcel in Loudoun's suburban east is very unlikely to carry this exposure. A parcel off a two-lane road west of Leesburg is a different conversation entirely.
The Law That Changes Your Closing Paperwork This Winter
House Bill 1358, sponsored by Delegate Runion, and its identical Senate companion, SB 649, sponsored by Senator Obenshain, cleared the General Assembly this year and were signed into law on April 6, 2026. Both take effect January 1, 2027.
The mechanics are specific. Settlement agents handling a transaction involving land subject to a special use-value assessment will be required to provide written notice to the buyer and obtain a signed acknowledgment. Willfully skipping that step exposes the settlement agent to a civil penalty of up to $250. Separately, the Real Estate Board has to add language to the statewide residential property disclosure statement, the form every Virginia seller already fills out, telling buyers that the seller makes no representation about whether the property sits in a locality with a use-value assessment program, and urging the buyer to do their own homework on potential rollback exposure.
For anyone closing on an enrolled Loudoun parcel after the new year, this means a new form, a new signature, and a new point in the process where the subject has to come up out loud rather than get buried in a title search.
What the Law Promises, and What It Doesn't
Here is where the story gets interesting, and where a seller or buyer relying on the new law alone could still get caught off guard.
According to Virginia REALTORS' own summary of the legislation, published in May, SB 649 was originally drafted to require a mandatory disclosure. It ended up, after the legislative process ran its course, as an addition to the existing buyer-beware statement instead. What survived is a guaranteed nudge. What did not survive is a guaranteed number.
Read the requirement again: settlement agents must notify and get acknowledgment that a special assessment exists. Nothing in the statute obligates anyone to calculate or disclose what the rollback would actually cost if triggered. The buyer walks away from closing knowing the risk is real. The buyer does not walk away from closing knowing whether that risk is $8,000 or $80,000, because the law that forces the conversation stops short of forcing the math.
That number still has to come from one place: a direct request to the Commissioner of the Revenue's office, asking for the parcel's current classification, enrollment history, and an estimate of what a rollback would trigger today. Nothing about the 2027 law changes that. It just makes the absence of that request harder to excuse.
What This Means If You're Listing or Buying Before Spring
The practical shift is timing, not substance. Anyone listing a Loudoun horse farm or acreage parcel this fall for a closing that lands after January 1 will be operating under the new notice requirements. Anyone closing before that date will not, though nothing stops a seller or buyer from asking these questions now regardless of which side of the deadline they fall on.
A few things worth doing before the paperwork changes:
- Confirm the parcel's current land use classification and enrollment history with the Commissioner of the Revenue's office before listing, not after an offer arrives.
- Ask specifically whether the property is enrolled under a standard five-year rollback exposure or a sliding scale agreement, since the sliding scale can push the lookback window well past five years.
- Get a written estimate of the rollback liability as it stands today. A verbal ballpark is not the same as a number the Commissioner's office will stand behind.
- Address rollback responsibility directly in the purchase contract if a change in use is anticipated after closing, since the statute itself does not automatically assign that cost between buyer and seller.
- Treat the January 2027 disclosure form as a floor, not a substitute for the county-level request above.
A Few Common Questions
Does selling the farm by itself trigger a rollback bill? No. Under Virginia's use-value assessment statute, a sale alone does not trigger rollback taxes as long as the new owner keeps the land in its qualifying use and does not request a rezoning to something more intensive.
What actually starts the clock? Changing to a nonqualifying use, rezoning to a more intensive classification at the owner's request, or splitting off a lot that no longer meets the minimum acreage for its qualifying use. Any of these can trigger the rollback regardless of whether a sale is involved.
Does the new 2027 law change how much is owed? No. HB 1358 and SB 649 change who has to raise the subject and when, through settlement agent notice requirements and updated disclosure language. The underlying rollback formula, the five-year lookback, the sliding scale provisions, and the interest calculation are untouched.
A Loudoun horse farm's tax history is not something a listing sheet volunteers, and after this January it still won't be, not in dollar terms. It takes someone who knows which office to call and which classification to ask about. If you are weighing a listing this fall or working through due diligence on acreage west of Leesburg, Horse Farms & Country Homes can help you get the actual number before it becomes a surprise at the table. Book an appointment to start that conversation now.
