What to Show an Inspector: A Night-by-Night Letting Statement

A letter arrives from the council. It asks how many nights your flat was let last year, or what share of the year it was available to book. You open your calendar, and that’s when you realise it only shows how things stand today.

Every block you added in June now covers days that were wide open in March. A channel feed you disconnected took its bookings with it. The calendar isn’t lying, but it can’t answer a question about the past. Whatever you send back will be a reconstruction, and the person reading it will know that.

Checked 27 September 2026. This is general information, not legal advice. Letting rules change often. Check the current rule with your authority, and ask them what form of evidence they accept.

What an inspector is actually asking

Night caps come in two shapes, and the evidence you need depends on which one applies to you.

A cap on nights let. London’s 90 nights, Paris’s 90 and Amsterdam’s 30 count what you sold. The question is how many nights were booked in the calendar year.
A cap on nights offered. Cape Town’s draft 50% rule counts what you made available, booked or not. The question is how many room-nights were open to guests over the window.

Both are questions about days that have already gone, and neither can be answered from current state. That’s the argument of A Night Cap Is an Accounting Problem. The short version: you need a ledger, meaning a record written on the day about the day, which later edits can’t rewrite.

Your records also have to add up across channels. Each platform sees only its own bookings. Since 20 May 2026, platforms across the EU report host activity to national authorities every month. So the authority may already hold figures for each channel. What it doesn’t hold is your total, unless you give it one.

What a useful statement contains

When we designed the statement, we asked what a sceptical reader would want to check. We came up with five things:

Which property, and its registration number if your city issues one.
The rule it was measured against: what was counted, per night or per room-night, over which window, and up to what limit. A number means nothing without the rule behind it.
The total, and the limit next to it.
Every night in the window, one row each, so anyone can recount the total themselves.
An honest account of how the record was made. Which days were written down on the day, and which were worked out later.

Most hosts can produce the first three. The last two are what make a statement something the reader can check.

The statement Airflow produces

Open the property’s settings and go to the Block Dates tab. The Letting limit card is there. Once you’ve turned on Track this property and picked a rule, a Download statement (CSV) button appears under the readout. It gives you a spreadsheet in two parts.

The header describes the measurement:

Row	What it holds
Property	The property’s name
Registration number	As saved in the same card, or “not set”
Generated	When you downloaded it
Rule	The rule you picked, for example “London (90 nights)”
Counts	“nights booked” or “nights offered”
Unit	Per night, or per room-night
Window	The start and end dates of the period
Bedrooms	Used for room-night rules
Counted / Limit	Your figure, and the line it is measured against
Observed days / Reconstructed days	How much of the record was written on the day
Disclaimer	See below

The body has one row per night, with six columns: Date, State, Offered, Booked, Observed, Bedrooms. State is where the night last stood when Airflow recorded it: open, booked, blocked by you, blocked by a channel feed, or unpublished.

The disclaimer is written into the file itself: “A measurement against a threshold configured by the property owner. Not a legal assessment of compliance.” That’s deliberate. Airflow measures and keeps the record. Whether you complied is for you and the authority to decide, and a statement that claimed otherwise would be worth less, not more.

The column that matters most: observed or reconstructed

Every row says observed or reconstructed, and the header gives the count of each.

Observed means the night was written into the ledger by the daily snapshot, which runs every night once tracking is on.
Reconstructed means it was worked out afterwards from your bookings and blocks. When you first switch tracking on, Airflow rebuilds the previous 365 days so the gauge is useful straight away rather than in a year’s time. It’s careful about this: a past night is only treated as offered if it was booked or the listing is live now. A draft listing isn’t assumed to have been on the market.

Reconstructed days are weaker evidence, and the statement says so in its own words. We could have left that line out. We think a statement that admits how much of it is inference is more believable than one that hides it.

What follows is the one practical point in this post: the observed record only starts on the night you turn tracking on. Airflow doesn’t record untracked properties in the background. Every day before you switch it on can only ever be reconstructed. If there’s any chance you’ll need to show your numbers next year, the time to start is now.

Read it before you send it

A few things to check before this file goes to anyone:

The count is only as complete as your imports. Airflow can only record bookings it can see. For a nights-let rule like London’s, a booking on a channel you haven’t connected is a night missing from the total. Import every channel, including direct bookings and any you took by bank transfer.
Past nights are final; future nights can still change. Once a night has passed, its Offered and Booked values are fixed as recorded on the night. A night still to come shows the calendar as it stood when you downloaded the file: close it and it stops counting as offered, and a cancelled booking stops counting as booked. The Final column says which is which, so an inspector can see exactly which part of the year is settled.
The header shows your current settings. It records the rule in force when you downloaded the file, not a history of changes. If you switch presets partway through a year, download a statement before you switch.
It covers the rule’s current window. For a calendar-year rule, that’s 1 January to 31 December of this year, including nights already booked for later in the year. For a rolling rule, it’s the 365 days up to today. You can’t pick an earlier period from the portal yet. For a calendar-year cap, download a copy in the last days of December and keep it.

Who can use it

The letting limit card, and the statement, work on any property in Airflow for anyone with an owner, admin or manager role on it. There’s no separate plan for it. If you manage more than one tracked property, the card also shows a one-line summary across all of them. You still download statements one property at a time.

What to do this week

The statement is only as good as the days behind it, and observed days only build up from the day you start. So:

Create an account. You can start free; a card is needed at sign-up.
Import your booking history from every channel. Paste your Airbnb or Booking.com iCal link, or upload a CSV. Include direct bookings.
Open the property’s Block Dates tab, tick Track this property, and pick your rule. Look up your city in Short-Term Rental Rules by Country, 2026 first. If your city isn’t listed, set the four values yourself under Custom.
Save your registration number in the same card, if you have one.
Download a statement now, look at it, and put a reminder in your calendar to download one at the end of every window.

Airflow’s short-term rental tools keep this ledger alongside your bookings, invoices and accounts, so the record of the year is also the one your accountant uses.

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