Why Guests Don't Fill In Your SIBA Form (And How to Fix It)

A recent Reddit thread asked a simple question: do guests actually fill in the check-in form their Airbnb host sends them?

The answers were revealing.

One guest admitted they'd never knowingly ignored one — but added: "a reminder 1–2 weeks before would be the sweet spot for my attention span." Another said they only completed it because they knew it was required by law. A third didn't even know where to find the form on Airbnb, asking: "Checking in Saturday and do not see where to complete this form. Where would one find it?"

That last comment is the one every Portuguese AL host should read twice.

Your guest has no idea where the form is. They're not ignoring it out of bad faith — they genuinely can't find it.

Airbnb Doesn't Help You Here

Here's the uncomfortable truth: Airbnb is not built around Portuguese law. SIBA — the mandatory guest registration system managed by SEF/AIMA — is your legal responsibility as a host. Airbnb won't prompt your guest to fill it in. It won't remind them. It won't even surface the form clearly if you've shared a link in your message thread.

The result? Guests arrive, check in, and leave — and you've just missed a legal filing that carries fines of up to €2,500.

This isn't a guest problem. It's a delivery problem. The form exists, the obligation exists, but the path from "booking confirmed" to "form completed" is broken.

Three Types of Guests — and Only One Fills In the Form

Based on what hosts report and what that Reddit thread confirms, guests fall into roughly three categories when it comes to check-in compliance forms:

The Willing but Lost They want to comply. They're not trying to cause problems. They just can't find the form, forgot about it, or assumed someone else would handle it. This is the majority.

The Law-Aware Complier They complete it because they know it's legally required. They're proactive, informed travellers — a minority, but they exist.

The Genuinely Indifferent They've never thought about it, didn't know it was a thing, and will comply if you make it easy enough — but won't go out of their way.

The insight here is that almost none of these guests are actively refusing. The barrier is friction, timing, and clarity — not unwillingness.

How to Dramatically Increase Form Completion Rates

The Reddit thread gave away the answer directly: "a reminder 1–2 weeks before would be the sweet spot."

Guests aren't ignoring your SIBA form. They're forgetting about it, missing it in a crowded message thread, or not understanding what it's for. Here's how to fix each of those problems.

1. Send the link at the right moment

Timing matters more than you think. Sending the check-in form link immediately after booking is too early — guests are in planning mode, not arrival mode. The sweet spot is 3–5 days before check-in. That's when the trip becomes real and guests are actually thinking about logistics.

2. Make it a standalone message — not buried in a wall of text

Your welcome message probably includes WiFi details, check-in instructions, parking info, house rules, and somewhere in the middle of all that, a link to the SIBA form. Guests don't read walls of text. Send the form as its own message, with a clear subject line and a single call to action.

3. Explain why it exists — briefly

"Please fill in this form" gets ignored. "Portuguese law requires all guests to register — it takes 2 minutes and protects both of us" gets completed. Guests respond to context. A one-line explanation of why the form exists dramatically increases completion rates.

4. Use a direct link, not a platform-embedded form

The Reddit commenter who couldn't find the form on Airbnb wasn't being lazy — Airbnb's interface genuinely makes embedded forms hard to locate. A direct, clean URL that opens on any device, in any browser, with no login required is always going to convert better than something buried in a platform's messaging UI.

5. Send one reminder

One follow-up message, 24–48 hours before check-in, for guests who haven't completed the form. Not two. Not three. Just one, framed as a helpful heads-up rather than a chase.

This Isn't About Nagging Guests. It's About System Design.

The hosts who have the highest SIBA completion rates aren't the ones who write the most persuasive messages. They're the ones who've removed every possible point of friction from the process.

That means: one link, sent at the right time, that opens instantly on mobile, asks for only what's legally required, and confirms submission so the guest knows they're done.

When the experience is that smooth, completion rates aren't a problem. Guests fill in the form the same way they accept the terms on an app — quickly, without friction, because it's clearly the next logical step.

The tools exist to build exactly that workflow. The question is whether you've set it up — or whether you're still hoping guests will find the form somewhere in your Airbnb message thread.

The Checklist for Better SIBA Conversion

• Send the form link 3–5 days before check-in, not at booking

• Make it a standalone message with one clear action

• Include one sentence explaining it's a Portuguese legal requirement

• Use a direct URL that works on any device without login

• Send one reminder 24–48 hours before arrival if not completed

• Confirm to the guest when their submission is received

That's it. No complicated tech. No pestering guests. Just the right message, at the right time, with the right link.

Running Alojamento Local in Portugal? EazyAL automates the entire SIBA workflow — guests get a link before arrival, fill in their own data, and submissions are filed automatically. No manual data entry. No missed filings.