Hi Mark,
Have a read of this article:
Ken's Tech Tips - SIM Cards
There's a link to an Ofcom ruling in 2018, which means that "mobile networks shouldn’t discriminate based on the device or the equipment you’re using to access their network" - so basically, you should be free to use any SIM in any device that you want to - so yes, you can use a phone SIM in a router.
I'm currently using two 4G links (Three & Vodafone), with both SIMs in separate Huawei B525 4G routers (I will soon install external antennae for these too, one omni-directional and one directional), which are then Load-Balanced with my slow PlusNet ADSL (2Mbps) broadband (which is the only form of fixed line broadband available in my location) - and this setup works very well. I'm using "phone SIMs" in both routers (which means I can also used the unlimited minutes by connecting a home phone to the RJ11 ports on these particular routers).
So: in summary: due to an Ofcom ruling in 2018, you can use any SIM in any device, the providers aren't allowed to discriminate or prevent customers from doing this - luckily for those of us who now rely on 3G & 4G (& for some very lucky people, 5G - maybe in my area within 50 years!!) for their main internet link due to no other realistic option being available.
So - providers *shouldn't* discriminate - and if they do, Ofcom may be interested to hear from you!
I can't understand why providers offer separate "data only" SIMs for the same (or higher) prices as those for phones that include texts & call minutes.
NOTE: Most (all ?) 4G routers allow you to send & receive SMS text messages via the router's web admin interface - but not many have an RJ11 connection for a phone (to use for VOIP and/or using the inclusive SIM minutes).
Kind regards,
Adam.
