Rent Guard

Rent Guard is for landlords who give their residents internet through ISN Free WiFi (flats, student housing, rooms to rent). It links a resident's internet to their rent: when rent is paid, the internet works; when rent is not paid, after a short grace period you choose, it stops. You do not have to chase anyone and you do not have to cut anything by hand.

It is off by default. Nothing changes for anyone until you switch it on, and it only ever applies to your Internal accounts (the named resident accounts you create under Free access → Owner & guest access).

1. Open Free access → Rent Guard in your dashboard.
2. Choose the grace period: 3 or 5 days after the due day.
3. Choose the speed during grace (download and upload, in Mbps). A resident in grace is slowed to this speed, never faster than their normal speed.
4. Decide whether residents are texted (this uses your SMS credits, or your own SMS gateway in Namibia).
5. Under Residents, give each resident a rent due day (1 to 28). A new resident starts as paid for the current month. You can also add your own reference for each resident (for example the flat number) which your own system can use through the API.
6. Tick Switch Rent Guard on and save. Residents whose rent is already overdue are put into grace, or cut, straight away, so start with their due days correct and rent marked paid for anyone who has paid.

Residents need a phone number on their account to be texted (South African or Namibian). The Residents list shows "No number" for anyone without one; they are still protected by the rules, they just cannot be texted.

Say a resident's rent is due on the 1st and you chose a 3 day grace period, and the rent for November is not marked paid:

With a 5 day grace period the same resident is in grace from 2 Nov to 6 Nov and unpaid from 7 Nov. Rent is checked every 10 minutes. Dates are in South African and Namibian time (both UTC+2).

The three SMS messages, word for word (your brand name is added at the start):

• Grace: "Your rent for 2026-11 is not marked as paid. Your internet speed has been lowered. Please pay your landlord. Your internet will stop on 5 Nov if rent is still unpaid."
• Unpaid: "Your internet has been stopped because rent for 2026-11 was not paid. Pay your landlord to get it back."
• Paid: "Thank you. Your rent is marked as paid and your internet is back to normal."

When a resident becomes unpaid:

• their internet unlock is removed and every device they used is disconnected at the router;
• they cannot sign in to their account, and cannot create guest vouchers;
• guest vouchers they created earlier stop working (the guest is simply told the voucher is not available right now, nothing about rent), and guests already online on those vouchers are cut;
• their devices are remembered and blocked. The router tells ISN each phone's hardware (MAC) address. Because of this, signing out, clearing the browser, signing in with a neighbour's account, registering a new guest account, redeeming a voucher, buying a data plan or watching ads does not get that phone online. Opening the portal on that phone shows a page like the suspended-portal page: "Your internet is paused. Rent for your home has not been paid." Only that resident's devices see it. The page does not say who or which flat, and nobody else is affected;
• The sign-in page and the home page close. A paused resident sees one full page, "Your internet is paused", in the same design as the page a suspended portal shows. It says only that rent has not been paid and to speak to the landlord, never whose rent or which flat. A resident who is signed in with the home page open sees it switch to that page within about 15 seconds, and a resident who types their password on the sign-in page is taken to it. It clears by itself once you mark the rent paid. The paused page cannot be opened by typing its address: it is shown only to a paused resident or phone. A resident whose rent is tracked must also sign in from a device that can be recognised (the portal's browser marker or the router's own record of the phone), otherwise they are asked to use their normal browser. This also holds for a resident who is roaming at a partner institution, and for a signed-in session that was open before a server restart.
• the block is checked wherever internet is switched on (the router, and UniFi and Omada controllers), not only on the website, so there is no side door;
• Partner Roaming is closed too. If your captive has roaming partners, a resident whose rent is unpaid cannot sign in at any partner institution with their account (they get the same "your internet is paused because rent has not been paid" answer, and only after the correct password, so nothing is revealed to a stranger). A roaming session they already have open at a partner is cut when rent becomes unpaid, and a phone that is blocked by its hardware address is blocked at the partners that accept your visitors as well. Paying brings it all back at once. A resident who is only in grace keeps roaming, and the lowered grace speed is not applied at the partner.
• the remembered devices are stored while rent is unpaid and deleted the moment rent is paid (or if you switch Rent Guard off).

Approve new devices by SMS code (optional, off by default). Tick this on the Rent Guard page and a resident's account used from a device it has never used sends a 6 digit code to the phone number on that account. The device only gets online after the code is entered on the sign-in page. A code is good for 10 minutes and 5 tries, at most 3 codes are sent per account per hour, and every approved device is listed in your activity log (never the code itself). Devices the account already used when you switch this on are not asked, but every other device is, including a new resident's first one, and a resident with no phone number on file is not asked (your log notes it). It uses your SMS credits. It does not stop a resident from asking a neighbour for the code, but it means the neighbour gets a text they did not expect and has to say yes. If the text cannot be sent, the new device is not let in. A phone is recognised by the signed marker the portal gives its browser and also by its hardware address as the router reports it, so clearing the browser does not make an approved phone look new. A browser that keeps no marker and arrives with no router address is asked to use the normal browser. Single sign-on logins are not asked (the identity provider already checked the person). An approval stops counting by itself when the resident's password or phone number changes (the next sign-in asks for a code, sent to the new number). Switching the setting off clears all approvals, and Reset devices on a resident's row clears theirs whenever you want. A code that was sent survives a server restart, and your activity log shows which device (masked) was approved, so a code passed to someone else shows up as a device you do not recognise. A device a resident adds with their own pairing code or a voucher that allows adding a device counts as approved.

If a neighbour lends their account to a blocked resident: that device is still blocked, so it does not work, and your Rent Guard activity log records that a blocked device tried to get online. The neighbour's own account is not blocked (they paid), and their own phone keeps working.

• Phones that change their hardware address. Most phones keep one address for each WiFi network, which is what ISN remembers. A phone set to use a new random address each time it connects (an optional setting on some phones) looks like a new device every time. ISN also remembers the browser's signed device marker, which covers the same browser, but a resident who both gets a new address and clears the browser looks like a new phone, and could then use a neighbour's account on it. Their own account stays refused while rent is unpaid, and your activity log notes every blocked attempt. As a second line, ISN also notes the browser's look (browser type, screen size and time zone) of a blocked resident's phone. If a phone it does not recognise shows up with the same look, the Devices that may belong to a blocked resident list on this page shows it and you decide with Block this device or Not them. ISN never blocks on the look alone, because a neighbour with the same phone model looks the same, and a resident who changes phone model or tampers with their browser will not match. If this matters in your building, ask residents to keep their phone's WiFi "private address" setting on the fixed option for your network.
• A resident who knows another person's phone address and fakes a sign-in link could try to get that phone added to their own list. Devices added after the cut (only from the resident's own sign-ins) are limited to a handful, are shown masked in your activity log, and are all released when rent is paid.
• Guests of a resident's vouchers lose their access when the resident is cut, but their phones are not blocked on their own account: they are visitors, not the resident.
• It does not take payments. You (or your system) record that rent was paid. Rent Guard never touches your money.
• Only Internal accounts. Regular guests, vouchers you create yourself, data plans and subscribers are not affected.

• In the dashboard: press Mark paid on a resident, or tick several and press Mark selected as paid. Reverse undoes this month's payment (for example when it bounced).
• From your own system: create a key under Connect your property system (API) and follow the integration guide. It has the secure signing steps and tested code for Node.js, Python, C# and shell. A key can only report rent paid or not paid for your own residents and cannot be used to damage anything else.

Marking paid is limited to the current month and the next one, so a mistake cannot give a resident months of free internet. Reverse (or an "unpaid" report from your system) never cuts anyone straight away: the resident gets a fresh grace period counted from that day. Every change is in the activity log with who made it (you, or which key).

Rent Guard works for both. A resident's phone number may be stored and sent in any common format (+27 71 123 4567, 0711234567, +264 81 123 4567, 081 123 4567, +268 7612 3456 and so on); ISN reads them all as the same number. A number written without a country code is read as your own country, set under Country & currency. In Namibia and Eswatini, SMS can go through your own SMS gateway.

Rent Guard keeps: each resident's rent due day, the last month marked paid, your reference, an activity log of changes, and (only while rent is unpaid) the hardware addresses and browser markers of the resident's devices so the block holds. It does not read your residents' browsing. The API never returns names, phone numbers or passwords. Device records are deleted when rent is paid or when you switch Rent Guard off. Tell your residents in your house rules or lease that internet is linked to rent.

What if I switch it off? Everyone gets their internet back at once and all remembered devices are deleted.

What if a resident pays on the day the internet stops? Mark them paid; they are back straight away. You do not need to wait for the next check.

Can residents tell it is me who cut them? The messages say rent is unpaid and to pay the landlord. Nothing else is shown.

Can I try it first? Give one resident a due day that has already passed, switch Rent Guard on, and watch the grace period work on that one account. Mark them paid to bring them back.