Avoiding roaming fees: forwarding incoming number via another provider to a foreign phone number or SIP-number

I’m wondering if anyone has a solution to the following problem:

  • I have a Swiss mobile phone number.
  • I’m often abroad where my Swiss mobile operator (actually every Swiss operator!) charges extremely expensive roaming fees for incoming calls (outgoing calls are not a problem, see below), even if I would buy special packages.
  • I have local numbers abroad.

What’s the cheapest way to have calls to my Swiss mobile number forwarded to my local number abroad (or, if that’s an option, to a SIP number, which requires me to be online all the time)?
One thing to consider: I have my Swiss number activated when I am abroad as I need it for the SMS service (account login, etc.).

And also for information: Calling a Swiss number from abroad is no problem at all, as I use the Dellmont service (VOIP), which allows me to call a Swiss landline number via the Internet/Android app for as little as CHF 0.005 per minute. My only problem is how to receive incoming calls on my Swiss number when I am abroad for cheaper (or let’s say for human fees, not like now as I would pay around CHF 5 per minute…)

It seems like you have data included in your roaming package as you mention calling via Voice Over IP (VOIP). So the best way to call you would be through Internet protocols like Whatsapp or FaceTime (audio).

You really have to understand that if somebody calls you on the regular mobile phone network, you will be using the foreign network and you’ll be charged at “voice” prices for roaming. If they call you through the Internet, you will be charged at “data” prices, which you seem to have included in your contract?

This Swiss operator provides a VoIP app and can route regular calls to the app. You can then use your foreign data plans to get internet and access the Swiss number through it. Would that help?

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First question: which countries are you travelling to? I don‘t think that roaming rates need to be expensive for Europe (+ US/CA) with most carriers.

Due to the calling rates your mobile carrier in CH charges, you‘ll most probably have to forward twice: First from your Swiss mobile number to a cheap „proxy“ in Switzerland. Then from that to your foreign local number (probably chargeable).

No, i do not have data included in my roaming package, but I do have a local SIM card in the foreign country with which I use the data. And I use VOIP with this local data plan in that country (I have a dual SIM phone, so SIM 1 is always my Swiss number and SIM 2 is always the data plan of the country in which I am at the moment).
And yes, I’m aware about the roaming fees. That’s why I do not use my SIM 1 (swiss number) at all when being abroad (except: passively receiving SMS for ebanking etc.).

That’s interesting. However, I do not see any information that incoming calls on the app are free, and if not free, I also don’t find information on how much they charge for incoming calls on the app in the country abroad. Do you have any experience with that? And I also guess it only works with a paid plan and not with a prepaid (which I would prefer since I use my phone literally only for receiving phones/SMS).

It doesn’t matter in which country I am, but believe me, every Swiss operator charges ridiculous high tariffs in these countries where I’m mostly. But if you need an example then take Uzbekistan.

And yep, that’s what I think too: it might have to be forwarded twice as you say it.

But there is another serious problem: As far as I understand if you let forward your call, let’s say, from a Swiss mobile number to a Swiss/German fixed line number (and then from there to, to take the example, an Uzbekistan number), and you’re abroad with your Swiss mobile number being registered in the network abroad (Uzbekistan) then this forwarding to the Swiss/German fixed line will not be calculated on the basis of “Swiss-Swiss/Germany tariff for calls from Switzerland” but on the basis of “Swiss-Swiss/Germany tariff for calls from Uzbekistan”, am I right? I contacted the other day M-Budget Mobile with this question and they confirmed: If I have a phone forwarding option but I’m in a foreign country then this will be charged according to the roaming fees of that country. So, this is a serious problem. And please keep in mind: I need to have my Swiss phone number being registered in the foreign network in order to receive the SMS (for ebanking etc.). So, to have my SIM card turned off before leaving Switzerland (and thus keep it technically still registered in a Swiss network) is no option.

You‘re with M-Budget Mobile? :sweat_smile:

They charged me 4.20 CHF/min for call forwarding to my own Combox number (!) just last month. Within Switzerland. That was my first experience as a Swisscom (which operate M-Budget mobile) customer. I wasn‘t impressed.

No, I am not with M-Budget Mobile but I just asked them about the technical aspect when forwarding to another phone number. With the free my country option it’s just CHF 0.03 per minute (prepaid).

But that’s not the problem I’m discussing here :wink:

…at least for conditional forwarding - i.e. when the call gets routed to the foreign network and „back to CH“ after you fail to pick it up.

If you, unconditionally, forward all calls, I think it will only charge you a domestic call for call forwarding. See for example here and here on Swisscom‘s community forum. I‘d also recommend setting that forwarding up while still in Switzerland.

PS: The Swiss carrier could, of course, determine that you’re abroad and „take back“ the call and then keep the call in Switzerland for domestic forwarding by employing so-called anti-tromboning measures. Swisscom was accused of actually doing that while still charging customers the more expensive roaming rate. I‘m not sure what came out of that.

So with your 2 SIMs, what I’d do is simple:

1)Keep your Swiss SIM in SIM1 to receive SMS abroad. I don’t know what operator you have, but I believe most of them don’t charge to receive SMS in a foreign network.

2)If someone calls you on your Swiss number, don’t answer. Call them back with your SIM2 with VOIP (presumably you’ve set your Swiss number as caller ID).

It will still cost you a bit to call back, but much less than using the foreign voice network.

Right, good point. Unfortunately I don’t have any experience with it myself.

I personally use the following trick:

  • SIM card from Salt. Enabled WiFi calling (I have a subscription, hope it works for pre paid as well). Disabled automatic search for a network (basically forcing it to use the Salt network or have no network otherwise). This is very important.
  • iPhone with dual SIM. The other SIM supplies internet when abroad. Thanks to WiFi calling being enabled on the Salt SIM and no network coverage, the phone automatically enables “Wifi Calling using Cellular Data”. It is a really cool feature I discovered accidentally and it works like charm. Salt does not charge for roaming for Wifi calling, incoming/outgping calls or SMS, all tested and works.

But if this call goes to voicemail then…

Well, not within Switzerland. But roaming fees do apply when forwarding calls to your voicemail. Awful.

Good point; definitively disable voicemail.

No, they really did do it within Switzerland.

People called me on my mobile, their calls got forwarded to my mailbox, and M-Budget charged me 4.20 per minute. I called back a within five minutes - while I was in Zurich (city).

After I complained, they sent me a text message admitting to an error in their prepaid billing system and promised to “automatically” recredit the amount erroneously charged to my account in January.

Here we are in February and the amount has still not been refunded to my prepaid balance. Though to be fair, I told them not to bother about my personal balance but just fix the error for their customers. I’ll be porting my number to a new subscription price plan anyways at the end of the month. I also disabled call forwarding after I became aware of the fees.

I understood that, and I am disgusted by this practice that makes no sense. Even if it’s just a “technical error”.

What I meant is that it is standard practice to bill redirections to voicemail when roaming, so better disable it before travelling.

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Thank you for this insighful information and the links, I didn’t know about that, also not conditional vs unconditional fowarding!

That’s exactly what I do at the moment! With Dellmont VOIP this is quite affordable. Actually, I even use Dellmont VOIP providers when being in Switzerland. Since ever I only have a prepaid SIM which I literally only use to receive phone calls and SMS. For all the outgoing calls and SMS I use Dellmont VOIP, wherever I’m on the world, having a data SIM in my SIM2. Many Dellmont provider also ovver the caller ID option for free.
However, I really would love to have also a setup just to accept phone calls also on my Swiss number when being abroad.

That is also quite interesting! I once read that WIFI calling abroad charges roaming fees, but obviously not every provider as your example with Salt confirms!

So, the setup, if I understand you correctly is: Disable automatic search for network on your mobile (for the SALT SIM card of course), have inserted in the other SIM the local data SIM and enabled on the phone “Wifi Calling using cellular data” for SALT SIM (or in general, maybe this option is valid for both SIMs). At the moment I have Aldi Suisse Mobile prepaid which I guess do not offer this. But I will do some research if other provider with good prepaid rates will offer that too. If it’s only SALT then probably other SALT-provider will have it too. I’ll definitely have a look into that! Thanks much again!

PS: Just to understand you clearly: this also allows incoming SMS, not only calls, correct?