Looking for an SMS only SIM, is there such a thing?

[#1]

I have an SMS gateway that I'd like to 'upgrade' the SIM on to one that will only be used to Send / Receive SMS messages. Does anyone know of a good provider that offers decent coverage where I can get a SIM from? I don't want to have to top-up every X days and ideally the credit would not expire.

[#2]

I have a PAYG 3G sim...... put on £10.00 and it lasts until it runs out.... same as for a payg phone.... if you just want to use "part" of what it covers then I see no problem with that.... e.g. my 3G sim has not been used to make any phone calls and only twice in the past 2 months have I used it to "surf" the net for directions on line... never used it for text messages...
similarly on my PAYG phone with T-mobile.... I hardly ever make phone calls... rarely send texts.... since last christmas when I put £10 before going away, I have just received a text saying my credit is only 97p.... and should topup soon... 

[#3]

A Three 321 sim would probably be best. 2p/sms no expiry on top ups.

[#4]

Both sound sensible options.
@shutter who is your 3G Sim with?
@Hairy How is that billed?

[#5]

You get a PAYG sim (I got a pre-loaded one cheap off ebay) then you are charged by the call/sms/Mb. (3/2/1p)

[#6]

Top-up Online, by Voucher or Cash Machine apparently.
There appears to be an add-on giving 3000 texts for £5 (expires after 30 days though): http://www.three.co.uk/Support/pay_as_you_go/Phone_tariffs

[#7]

You also get some free calls/sms/Mb when you top up, (or buy it topped up) that lasts for 30 days. Can't remember the details but it was something like 150Mb free

[#8]

Well considering the advice I've had I'me still confused. The SIM sits in my SMS gateway and I talk to it via telnet with messages being sent using AT commands. I don't want to interact with the card at all so an option where I top it is topped up remotely would be best, and from what I understand this can be done at a supermarket checkout?
And before anyone asks no I don't have a mobile of my own.

[#9]

As for signal strength, OFCOM have mapped the mobile operators signal data here http://www.ofcom.org.uk/mobile-coverage

[#10]

Quote from: Mook

I don't want to interact with the card at all so an option where I top it is topped up remotely would be best, and from what I understand this can be done at a supermarket checkout?

Three SIM cards can be topped up online using the three website.

[#11]

Well that's even better news as using that (rather useful) link from georgelnx it needs to be either a Three or EE, there's no coverage from the other two providers (welcome to sticksville).

[#12]

My 3G sim card is from a supplier on Ebay..... !... I think I paid about £8.50 for it, including p&p. with £10.00 credit on it..... (work that one out for value ! ! ! )  HairyBiker put me on to it... it runs on the 3 network...
EE/T-mobile can be topped up in most supermarkets at their service counter... ( not sure if you can do it at the till )... or most local "convenience" shops... ( one stop, McColls etc ) local corner shops where you can get a mobile phone top up.....
You just go in there and say to the cashier..... £10 T-mobile topup please..... they print out a " receipt "  with a 15 digit number on it... and you have to put that number into the phone on a specific dial up number ..( inidcated on the receipt)...
Alternatively... I use a plastic card where Igive that to the cashier... they "swipe" it and I hand over £10 ... and job done... (5 minutes later, a text appears saying top up successful ) ...  no faffing about with 15 digit numbers...

[#13]

@shutter What you have sounds perfect for me are you able to provide me with a link?
I can't find anything on either EE or 3's website that doesn't cost £X per month. All I want is to have a SIM that when I credit it the money on it never expires. The system is used to send alerts meaning that a £10 top up could maybe last 3 month at 10p per message.
The ability to update the card without user interaction is a must, as I can't pull it from the gateway each time it needs topped up.

[#14]

Full price direct from 3: http://www.three.co.uk/Store/Pay_As_You_Go_Price_Plans
Cheapest I could find (didn't spend long searching though): http://www.ebay.co.uk/itm/Three-3G-10-Preloaded-SIM-Card-with-321-plan-STANDARD-MICRO-or-NANO-sim-/1...
Easiest top-up is by registering a 'My3' account online: https://www.three.co.uk/My3Account/My3/Register?intid=globalregister

[#15]

w23 has given a linky to the ebay seller... ( or at least ... one of them.... )  can`t remember if that was the same guy... but that is a very similar deal...