The VAT Threshold Trap for Growing STL Portfolios: The Cliff Edge Nobody Warned You About

In short: STL income is subject to VAT registration at the £90,000 threshold, on a rolling 12-month basis. Growing operators frequently pass the threshold without noticing, and the cost of retrospective registration is materially larger than the cost of proactive planning. This piece sets out the four options available to an operator approaching the threshold, and why the DIY approach usually costs money.

Short-term let income is taxable turnover for VAT purposes. This surprises a lot of new operators. Long residential lets are exempt; short-term lets of the type most of our clients operate are not. Once your rolling 12-month turnover exceeds the VAT registration threshold (£90,000 from 1 April 2024), you are required to register with HMRC and to start charging VAT on your bookings.

The mechanics are the surprise. This piece is what we tell every operator who is scaling a portfolio.

The rolling 12-month test — and the 30-day forward look

There are two tests, run in different ways.

The historic (backward-looking) test. At each month-end, compare your total taxable turnover for the previous 12 months against £90,000. If it exceeds £90,000, you must notify HMRC within 30 days; registration takes effect from the first day of the second month after the crossing. A monthly diary entry works well for this test.

The forward-look test. If at any point you reasonably expect your taxable turnover in the next 30 days alone to exceed £90,000, you must notify HMRC by the end of that 30-day period, and registration takes effect from the start of that period. This test can arise at any time, not only at month-end — a large deposit received, a corporate booking confirmed, a Festival-week booking taken can trigger it independently of the trailing 12-month figure. A monthly routine alone will miss it; the forward test must be monitored continuously.

Both tests apply. The historic test catches gradual crossings; the forward-look test catches sharp ones.

Why STL income makes the threshold trap worse

Three features of STL turnover compound the issue:

Deposits create a tax point on receipt. Under section 6(4) VATA 1994, a payment received before the supply creates a tax point on the date of receipt for the amount received. An operator who takes £30,000 of deposits in April for August stays has £30,000 of April tax-point value — it counts against the trailing 12-month test in April, not August. Operators who track only "stayed nights" understate their VAT turnover and miss the crossing.

Platform fees do not reduce turnover. The turnover figure that counts for the VAT threshold is the gross booking value, not the net paid out by the platform. An operator whose Airbnb dashboard shows £75,000 of net paid-out income may have £90,000+ of gross turnover for VAT purposes.

Reverse-charge platform fees may count against the threshold. Where a UK-based host receives services from an overseas supplier such as Airbnb Ireland or Booking.com Netherlands, the reverse-charge mechanism applies to those services if they fall within the general place-of-supply rule for services to business customers. The value of the reverse-charged services counts towards the £90,000 registration threshold for the recipient — this is the trap that catches many otherwise below-threshold operators. Check the actual supplier, invoice and treatment on your own account: platform arrangements can vary by country, host category and whether the host has supplied a VAT number (VAT Notice 741A section 5).

Take a hypothetical operator with £83,000 of accommodation turnover and £8,000 of platform commission subject to reverse charge — combined £91,000 crosses the threshold. An operator at £82,000 plus £8,000 is exactly at £90,000, which on the "exceeds" test does not cross. Precision matters.

The options at the threshold

Once you can see the threshold approaching, four routes are worth considering:

Option 1: Register and pass the cost through. Add 20% VAT to prices, register with HMRC, reclaim input VAT on eligible expenses. Often the right answer where guests are business travellers or corporates who recover input VAT.

Option 2: Register and absorb. Keep prices flat and take the VAT hit on margin. Real margin compression, sometimes the least-bad answer for price-sensitive leisure segments.

Option 3: Consider the Flat Rate Scheme. The published FRS category rate for hotel / accommodation is 10.5%. Newly VAT-registered businesses get a 1 percentage point discount in the first 12 months, reducing the rate to 9.5% in year one. The limited-cost-business rules impose a 16.5% rate on businesses whose relevant goods purchases are below defined thresholds — many STL businesses fall into this category, which can eliminate the FRS advantage entirely. The FRS percentage applies to VAT-inclusive turnover. The scheme's own eligibility thresholds are on different bases: entry is at £150,000 VAT-exclusive taxable turnover in the next 12 months (measured on a forecast basis); exit is triggered when VAT-inclusive total business income in the last 12 months exceeds £230,000. Modelling is essential (HMRC — VAT Flat Rate Scheme rates; HMRC — Limited-cost business tests).

Option 4 (check whether TOMS applies). TOMS is not an elective substitute for ordinary VAT that a business can pick because it gives a better answer. Where the supply falls within the TOMS scope, its rules govern the VAT treatment; where it does not, they do not. Whether an operator's arrangements are within TOMS is a fact-and-contract analysis, not a business choice. The Upper Tribunal in HMRC v Sonder Europe Ltd [2025] UKUT 14 (TCC) held that Sonder's specific rent-to-rent serviced accommodation model failed the TOMS tests — the accommodation acquired under longer leases was not supplied to travellers without material alteration, so VAT was due on the full amount received. Sonder's decision is fact-specific and does not settle the position for every rent-to-rent model; take targeted advice on the specific arrangement. Check whether the decision has been appealed further before treating it as final.

The disaggregation risk — two distinct mechanisms

Splitting a portfolio into distinct legal entities to keep each below the threshold is challenged by HMRC where the entities are commonly controlled and operate as one economic unit. Two separate statutory mechanisms need distinguishing:

• Notice of direction under Schedule 1, paragraphs 1A and 2, VATA 1994. HMRC can direct that persons who have artificially separated business activities are to be treated as a single taxable person. The direction takes effect from a date HMRC specifies going forwards — it does not itself backdate liability.
• Finding that a single taxable person always existed is a distinct question. HMRC can assess for historic under-registration where the facts show that what looks like several separate entities has always operated as one economic taxable person — a higher evidential bar than the forward-looking direction and dependent on the specific arrangement.

Section 43 VATA 1994 is a different provision entirely — it concerns VAT grouping (a voluntary election for eligible corporate groups to be treated as a single taxable person). Do not confuse the two.

Getting the ownership and operating structure right at set-up avoids both routes. Trying to unwind a disaggregation challenge is expensive and case-specific. HMRC's disaggregation guidance is in the Notices of Direction manual.

The cost of getting it wrong

Retrospective registration is worse than proactive registration. HMRC will register you from the effective date, assess VAT on output turnover from that date, charge interest on the unpaid amounts, and consider a failure-to-notify penalty. Penalty rates depend on whether the failure was deliberate or non-deliberate, whether disclosure was prompted or unprompted, and how the taxpayer engaged with HMRC. The bands are set out in Schedule 41 Finance Act 2008 and can range from 0% (unprompted disclosure of a non-deliberate error corrected within 12 months) to 100% (deliberate and concealed prompted disclosure). Get advice on the specific circumstances rather than relying on a headline figure.

What growing operators should do

1. Review the rolling historic turnover test at each month-end, and monitor continuously whether you expect taxable turnover in the next 30 days alone to exceed the registration threshold. A monthly diary entry alone can miss the forward-test trigger.
2. Include reverse-charge platform-fee value in the calculation where the reverse charge applies to your supplier arrangement.
3. Model the pricing decision (pass through / absorb / FRS) before registering, not after.
4. Consider VAT at every acquisition. For portfolios near the line, the marginal property may push you over; factor the crossing cost into the deal.

Book a free consultation to talk through your specific position.

Sources: HMRC — Register for VAT; HMRC — VAT Flat Rate Scheme; HMRC — VAT Notice 741A: place of supply of services; Schedule 41 Finance Act 2008 (failure to notify penalties); HMRC v Sonder Europe Ltd [2025] UKUT 14 (TCC).