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

The threshold is applied on a rolling 12-month basis, not a fiscal year. This means:

• At the end of each month, you compare your total taxable turnover for the previous 12 months against £90,000.
• If the total exceeds £90,000, you must register with HMRC within 30 days.
• Registration takes effect from the first day of the second month after you crossed the threshold.

For an operator adding properties through the year, the threshold can be crossed mid-summer with the next 12 months' peak season still to come. Delaying registration in the hope that a quiet autumn will bring the trailing average back below the line is not a strategy - the crossing has happened, and the registration obligation is fixed.

Why STL income makes the threshold trap worse

Two features of STL turnover compound the issue:

Booking income is recognised when the stay happens, not when the payment is received. An operator who has taken £30,000 of deposits in April for August stays does not have £30,000 of April turnover for VAT purposes. This gets missed on internal spreadsheets that track cash rather than turnover.

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 paid-out net income may have £90,000 of gross turnover for VAT purposes. This is one of the most common misreadings we see.

The four options at the threshold

Once you can see the threshold approaching in the trailing 12-month view, you have four options:

Option 1: Register and pass the cost through. Add 20% VAT to your prices, register with HMRC, and reclaim input VAT on eligible expenses. This is often the right answer for operators whose guests are business travellers or corporate accounts, because those guests recover their input VAT and are relatively price-insensitive.

Option 2: Register and absorb. Keep prices flat and take the VAT hit on the margin. For portfolios where the operator has genuine pricing constraints (competitive rack rates, price-sensitive leisure guests), this is sometimes the least-bad answer, but it is a real margin compression.

Option 3: Use the Tour Operators' Margin Scheme (TOMS) or the Flat Rate Scheme. Both are simplifications for smaller and specific businesses. TOMS in particular has application in some STL structures. Both require specific eligibility analysis - the wrong scheme on the wrong business creates more work than it saves.

Option 4: Restructure to stay under. Splitting a portfolio into distinct legal entities to keep each below the threshold sounds appealing but is aggressively challenged by HMRC as "artificial disaggregation". Where two entities are commonly controlled and operate as one economic unit, HMRC will treat them as one for VAT purposes and back-date registration. This is not a viable planning strategy for most portfolio operators.

The cost of getting it wrong

Retrospective registration is materially worse than proactive registration. HMRC will:

• Register you from the correct effective date (i.e. two months after the crossing you missed).
• Assess VAT on all output turnover from that date, whether or not you charged it to your guests.
• Charge interest on the unpaid amounts.
• Charge a penalty for late notification, typically 5-30% of the underpaid tax depending on delay and behaviour.

The cash impact of finding out you were VAT-registerable eighteen months ago is usually a five-figure sum. The cost of a specialist accountant to run a monthly trailing-12 report is a fraction of that.

What growing operators should do

1. Get a monthly trailing-12 turnover report. Whatever accounting system you use, this should be a standing report.
2. Model the threshold crossing at least a quarter ahead of when it will happen. By the time it happens on paper, it is too late for tactical planning.
3. Decide on pricing strategy for post-registration BEFORE registering. Guest expectations set at pre-VAT prices are hard to move.
4. Consider the VAT question when acquiring your next unit. For portfolios just under the line, the marginal property may push you over - factor the VAT cost of that crossing into the acquisition case.

Book a free 15-minute consultation to talk through your specific position.