MiFi routers

I’m looking for a way to set up WiFi for a building used occasionally. I don’t want to be paying monthly charges, so I’m thinking of the pre-pay SIM route – where I would put some credit on the account, which in some cases lasts for 6 months. We’ll use it within that time.

A bonus of this method is that we could move the router to a different location if necessary – for example when we go camping.

When the building is not in use the power is turned off.

The problem I see is that the routers all seem to be battery powered. In our situation the battery will probably run down, and I need a router that will start up when the power is turned on. I’ve checked with TP-Link (one of the suppliers), who tell me that router would need to be started up manually.

The current router is a standard domestic unit connected to a copper phone line. That does start successfully. The problem is that the price is rising, and in 2025 the government aim is to shut down the phone lines, forcing us to fibre, and even higher costs.

Where can I find information that will point me to a suitable unit?

(We can achieve this using a phone as a router. However it’s not ideal as it means finding a way to reimburse the phone user for any data changes.)

ASUS routers have a dual WAN feature, in that they can either operate from a wired WAN (ADLS or fibre), or they can fail over to a USB 4G/5G dongle. They will also come up automatically when powered.

Thanks. I’ll look into them.

I’ve got a Dlink DWR 920 and a ZTE MF286D, my daughter has a TP-Link TL-MR6400. All are mains powered and have both WiFi and wired LAN ports and a SIM slot so are self contained and start up without intervention when mains is applied.

The Dlink and TP-Link can be had for approx £65 – £70 new and are unlocked. The ZTE is approx £50 reconditioned and are usually supplied locked to 3 but can be unlocked with a bit of hacking.