Guest Wi-Fi with a Captive Portal for Cafes, Hotels and Clinics
Practice4 minInnovialabs editorial team
In short
A captive portal is the page guests see before getting online, where they log in by SMS, voucher or a button, accept the terms and give consent; pick the login method that local law requires, limit sessions and keep the guest network separate from the work one.
The short answer
A captive portal is a login page that opens when a guest connects to Wi-Fi. Until they meet the condition — enter an SMS code, a voucher or accept the terms — internet access stays closed.
For a cafe, hotel or clinic it solves three tasks: it controls who uses the network, limits the load and, with the guest's consent, provides a contact for marketing.
How it works
- The guest connects to an open or password-protected guest network.
- The controller or router intercepts the first requests and shows the portal page.
- The guest completes authorization.
- The system opens access for that device for a set time.
The portal can run on the router itself or the access point controller, on a separate server, or in a cloud service connected to your hardware.
Login methods
| Method | How it works | When it fits |
|---|---|---|
| "Accept terms" button | No identification | Where the law allows it and no records are needed |
| SMS code | Guest enters a number and receives a code | When phone-based identification is needed |
| Voucher | A code on the receipt or a card from staff | Hotels, coworkings, paid access |
| Room number and surname | Checked against the booking system | Hotels with PMS integration |
| Social or messenger login | Sign in with an account | Marketing scenarios |
SMS login requires an SMS gateway, and each message costs money — factor it in. Vouchers work well where guests already deal with staff: reception, the checkout counter.
Session limits
Without limits, one guest downloading torrents can slow the network for everyone. Configure:
- session time — for example, the length of a visit, after which the guest logs in again;
- speed per device — so the bandwidth is shared fairly;
- number of devices per code or phone number;
- idle timeout — disconnecting inactive clients.
Exact values depend on your bandwidth and the number of guests: start with moderate limits and adjust to the load.
Marketing data and consent
A portal can collect phone numbers, emails and visit frequency. That is valuable, but it needs care:
- separate marketing consent from accepting the Wi-Fi terms — its own checkbox, not pre-ticked;
- explain on the page what data is collected, why, and how to unsubscribe;
- store the data securely and only for as long as permitted;
- do not hand the database to third parties without a legal basis.
Legal requirements
Many countries have rules for public Wi-Fi: mandatory user identification, keeping connection logs, requirements to store personal data inside the country. These rules differ and change, so check the current regulations with a lawyer or your provider before launch, especially if you plan a login without identification.
Hardware options
- A router with a guest portal feature — for a small cafe with one or two access points.
- An access point system with a controller (cloud or local) — for a hotel or clinic across several floors: one network, roaming between points, a shared portal.
- A cloud hotspot service on top of compatible hardware — ready SMS login, vouchers, analytics and data export.
- Your own portal on a separate server — when you need integration with a CRM, the hotel PMS or a loyalty system.
Guest network security
- The guest network is isolated from the work network: POS terminals, medical systems, cameras and NAS must be unreachable.
- Turn on client isolation so guest devices cannot see each other.
- Use a separate VLAN and, where possible, DNS filtering.
- For clinics this is especially important: patient data must never share a network with guests.