Long-life SIM cards in Europe

In Germany, you can use Aldi talk. If you buy a credit for 30 EUR the SIM-card will be active for 24 months.

Another plus point is that you can use the SIM-card in the whole EU and it will not be very expensive - incoming calls are free, the outgoing call rate is the same as in Germany.

Although it varies from network provider to network provider, from my experience, many base it on how much credit you buy at a time. For example, if you buy a $30 top-up, that credit might only be valid for 30 days, however, if you top-up for $100, that credit might be valid for up to 1 year.

In Italy IIRC most of the providers maintain the SIM card active for 11 months or one year after last activity. According to this (Italian) webpage, many providers have a 12 months expiration period. CoopVoce's SIM has a validity of 24 months, though in the last month you can only receive calls. Wind, for instance, deactivates it after 12 months but maintains the number available for reactivation for another 12 months.

In case you can top-up online, you can always opt to "refresh" it every now and then, by putting small amounts of credit on the sim.

Tariffs within Europe are quite convenient due to regulations, and may become the same as national ones in the near future (also due to legislation).

I personally have a simyo starter 9cent card that I occasionally (around every 9 months) top up via their web interface. It has a validity of 24 months, and you can re-start it's validity when you top it up. It also has quite okay data connection package (€4.90/month for 200Mb, after which you are only slowed down for GPRS speed, and don't have to pay more - completely fine for occasional checking of mails). Data rates without a package is €0.23/MB, which is kinda expensive compared to their Flat Internet Minimum tarif though.

It's also perfectly useable outside of Germany for calls and texts as it's rates are completely reasonable if you are outside of Germany: €0.09/min to call and €0.07/min to text. Receiving calls are also free in the EU, which makes this tarif really useful even if you are outside of Germany. Note however, that if you call non-German EU numbers, while inside Germany the rates are a higher at €0.29/min (yes, it costs 3x as much than if you are calling non-German EU numbers abroad), so be careful.

For data connections outside of Germany I'd still buy a local SIM though, as data rates are still (in my opinion) expensive (€0.23/MB or €4.99/7days/100MB) for roaming purposes (which will hopefully change soon). Therefore I also have the following cards for data connections when I'm not in Germany:

• UK: Lebara UK plus 150 (only valid for 84 days, so you have to throw it away and get a new one every time. A SIM card only costs £1 - approx €1.2, and can be bought at every airport and international train stations, so it might not be a big issue). It doesn't contain unlimited data, but it might be enough for occasional browsing. Lebara also gives you 1MB of data every day for free, which can be useful.
• Sweden: Halebop rubbet. Valid for 12 months, but a top-up of 249 SEK will only contain inland calls (200 separate calls independent of call length) and data (3GB, which should be more than enough for travellers). Unfortunately the SIM card in itself is quite expensive (100 SEK which is approx £10 or €12), so you only should get it if you plan on visiting Sweden more than once in a year, or you need to browse the Internet, as it's still the cheapest throwaway card if you need data connection there.
• Hungary: I have a basic Telenor Praktikum SIM card which is valid for 180 days, but you can top it up, and then the validity will be extended to 12 months You can do this via their web interface even from abroad. The rates are not that good though, but the data packet will also only limit you to GPRS speed after you use it up, so it's fine for occasional browsing if you happen to be in Hungary.

Note that the rates are valid as of writing this post (20 June 2014)

As you mentioned Switzerland, here's an option for Switzerland.

M-Budget Mobile's prepaid card expires only after 12 months, after which you can reactivate it (and get back all your credit) in the following 6 months by calling their hotline. So you have a total of 18 months before your number is disabled. You can find this information on their FAQ under "Wie lange ist mein Guthaben gültig?".

I was never aware of that rule before I looked it up, but I've had an old phone with one of their SIM-cards for years as travel backup and I use it approximatively once a year. I always wondered why it never got deactivated.

T-Mobile in the Netherlands at least keeps your prepaid card active for 6 months after last use (though special discount rates and things like that usually have to be used up faster than that). That's the longest I know about.
Use there can mean using the card or adding credit to it (which you can do through their website).
You might check if the latter applies also to whatever card you have now. Of course if you just need to send a text message once every 2-3 months to keep the card active, and the card allows roaming to your current location, that's also an option. Just mark it in your calendar :)

I had one of these never ending sims, for a while. It was even their marketing trick some years ago to convince people to change to their offers. However, they just got merged into one the majors, who suddenly changed their regulations and conditions and because of this I lost my prepaid number.

So even if you secure one of these sim cards, you might end up loosing is in a year.

Another solution might be found in VOIP. There are different providers who offer you a VOIP number. The benefit of such a number is that with a German phone number you might even be available in your own country, as lang as you have access to the Internet. I am a customer of nomado.eu who do offer german numbers.. Normaly voip numbers are landline numbers, however apps exist to use those numbers on your smartphone. Nomado, for example has an app available.

You would still need a internet connection with your smartphone, but for that your could remain buying prepaid numbers each time you visit Europe.

Whilst on holiday to Slovakia I bought a prepaid (T-mobile) sim card just like you and although the official documentation said that it would expire after 3 months, when I arrived at the shop a year later they just said that when I topped it up it would re-activate again and that that was standard procedure. I have no idea in which other nations or which other providers this is the case, but it's definitely worth checking.

In Germany, Fonic (and Lidl Mobile, which is basically the same product under a different branding, but cheaper) offer prepaid cards with unlimited validity and reasonable data packages that can be booked via SMS or online.

They both use the O2 network, which is a bit congested in crowded areas as far as mobile data is concerned, but if you're mainly using it for calls and light smartphone data usage, you're probably going to be fine.

Update (2015-01-23): Unfortunately, Lidl has switched operators for their product (they now use Vodafone's network). Since then, the 5GB data package is no longer available for the generic "voice" SIM. It can only be enabled on the "data" SIM that is only sold together with a USB 3G modem.

There are two companies you can buy an international sim card. Its also a pay-as-you-go service without any contract but it does not expire and it does not rely on roaming. What is more, you can have the same number EVERYWHERE. You can check what they charge and decide. Its not very cheap but its ideal for those that travel regularly like you do.

sims2go and planetsim are the two companies.

hope that helps ;-)

Giffgaff and Three SIMs expire after six months of inactivity - most other UK operators are one month.

In Hungary, T-Mobile provide "DOMINO" (pre-paid) SIM cards with 12 months validity time.

Wait a little longer. Because Neelie Kroes (European commissioner) has a single rate for whole europe as a keypoint. The EU works towards roaming free europe by 15 december 2015. (source http://www.iphoneclub.nl/326009/commissie-europarlement-stemt-in-met-afschaffen-roaming/)

roaming tariffs in europe: http://ec.europa.eu/digital-agenda/en/roaming-tariffs

so the answer to your question is: get a cheap subscription, stop buying prepaid sims. Just pick one in the country that you visit the most.

edit to respond to the comments:

Perhaps registering a sort of border address (sorry for german link) http://www.grenspostadres.nl/assets/media/pdf/Deutsch.pdf

But all these tricks make it more expensive then a prepaid card. https://www.simquadrat.de/ seems to be valid for ever. no expiration. source: http://www.toytowngermany.com/lofi/index.php/t302356.html

There's an online service called Twilio that lets you buy phone numbers in a lot of courtries for one dollar a month.

Using their website, you can program some funny things to do with those numbers.

One of them is : forward to another (international) number

So you can buy a permanent number in France and in Germany and let them forward to your UK phone if you want.

My German T-Mobile was active many months after I've stopped to load it. There's no information how long it is to be active... I'm using also Lebara for foreign calls, last time I've loaded it over a half year ago, I still use it (one few-minutes call to Poland costs about 25 cents...) and it's still active. I can't say if it's permanently, but there's no information that I must load it now. I suppose, as long as you have some euro on it, you can use it.

There is, however, no clear information under which criteria the number will be disabled. Surery, at least in case of T-Mobile, a few months without turning phone on is not enough to deactivate the card.

In Poland, prepaids have limited time after loading, and afterwards you must buy minutes to prolong the number, but Play is active 1 year after loading for at least 10 PLN (2,5 EUR). It's almost no-cost to keep the number active. It doesn't matter if you turn the phone with the card on or not in that period!

You might be interested in Airbalticcard

• 10-15$ Pre-payed card (no monthly fee)
• Free incoming roaming calls almost all around the world
• Expiration after 2 years if there is no activity at all
• Extra money refundable on request if you stop using it
• Interesting rates given you will mostly be using this card only in roaming mode.
• Free call forwarding
• Data packages available in some countries
• Reduced price from Airbaltic to Airbaltic cards.

Drawback:

• Delay experienced while using the call forwarding (sometimes it's even not usable)
• (Always?) more expensive than a local provider
• Data packages not always available and still more expensive also
• Based on callback, once you call you actually have to wait for the central to call you back. It works quite well though.
• Callers actually pay your roaming
• Estonian phone number (with prefix +372)

In Portugal they expire by default in 3 months. However if you make a phone call or send a message before expiring the card will be extended for another 3 months.

I know this isn't a perfect solution, but no carrier is allowing you to own an unused number for more then 3 months.

I would recommend using a travel sim card when you travel around Europe. I normally use a Tellink traveller sim which works out perfectly and is cheap but not as cheap as local simcards of course. You can also use it in every country.

Lyca Mobile may have an interesting offer for you.

They offer free voice connection in Lyca network, where Lyca exist. For example, you can call for free from Polish Lyca to British Lyca or ... Lyca in India. This is very cool. Minus is that, validity is only 3 months after last top up. But can top up via their website.

For UK you can use tello.co.uk, their pay as you go credit doesn't expire and they say that they keep your SIM active for 6 months. I have it from Nov 2014 and didn't use it for almost 9 months and it was still active when I spend my Christmas holidays back home. They have low rates and the signal in good inside the city

1. In Poland I recommend You wRodzinie network (the same owner as one of the biggest polish network - Plus. So wRodzinie uses their infrastructure). With wRodznie, there is a TWO years validity, no need to top up. Network exist few years. I use for 2-3 years.

2. For internet I recomend You polish FREE data network - Aero2. This is for totally for free. You can't talk, this is only for Internet. And you must have one of the few USB modems, and not every smartphone works with Aero2. But this is FREE network. Website: Aero2 (unfortunately only in polish :( )