FP2 kills some SIM cards

Update: FP2 kills SIM cards from german Telekom – T-Mobile D, congstar, T-Mobile A - see posts below.

I can not simple activate SIM 2, i have to reboot.

  1. SIM 1 is active, SIM 2 is off
  2. switching on SIM 2
  3. FP says SIM 2 is activated but still no service
  4. waiting -no service
  5. airplane mode on and off
  6. still no service on SIM 2
  7. reboot -> service on SIM 1 and 2

I still have experienced that I’m loosing service on SIM 2 sometimes and have to reboot.

My setup:
living in Austria (SIM 1 (personal) - austrian provider), working in Germany (SIM 2 (business) - german provider)
At weekend only SIM 1 is active, mobile data switching between SIM 1 and 2, depending where i am.

Anyone else experiencing this problems?

There is a poll below to find out which SIMS/Providers are affected.

1 Like

Is your German provider Congstar?

Hi Irina,
no, my german provider is Telekom.

It’s getting worse.
Since yesterday my FP2 did not detect my Telekom (D) SIM card at all. Before that i did not get a service with this SIM card, but the card itself was detected.
I tried to change the SIM card slots, tried to switch off and let the battery out of the phone for some time. …by the way, ther seems to be another bug: i switched back on the phone (just my austrian provider, mobile data roaming off) and i was hours back in time. I had to manually set the time.

I will try the SIM card with an other phone when back home. The SIM is about 6 months old.

Update of topic title: the problem is that the FP2 is killing some SIM cards. In my opinion this is another bug. A very big one.

My German Telekom SIM card is no more usable after some weeks in the Fairphone 2. FP2 and
other phones will not detect the SIM anymore. The SIM is about 8 months old and type C/W7.

There is still a discussion in the forum, i am not the only person affected. It seems
this is the same/similar bug than users of oneplus, one LG and other phones have
This is what I have understood from reading in some other forums:
The German Telekom – T-Mobile D, congster, T-Mobile A – uses some additional services on
their SIMs. The affected phones (also the FP2) are allowing this services but
could not handle it and give an error message back to the SIM. The SIM gets the
error message and starts again with asking the phone to start the services, the
phone allows it, the service tries to start, the phone can’t handle it, gives
an error message. This is an endless loop until the maximum write/reads of the
SIM are reached (4-5 weeks). For my understanding the error handling of the SIM
is buggy (endless loop), but the origin bug is on the phone (allowing SIM
services which are not executable).

As read in other forums all the SIMs from Telekom are affected (C/W2, C/W7). There is a
C/V7 which seems to keep alive longer.
There is a special SIM – C/T6 - which has solved the problem for the oneplus users.

I have to try to get such a SIM, but in the meantime my business number is dead.


I just can report that I am observing the same behavior with a SIM from Telekom. The explanation that there are plenty of writes/reads to the SIM Card is also supported by the fact that the CPU of the fairphone gets rather hot, which might be due to the Loop of acceses to the SIM. My SIM Card is an C/W7 type. I switched now to slot 2 in the FP2 and it seams to work again - I will watch what happens and continue to report. Did you receive an C/T6 by Telekom in the meantime?

1 Like

Hi gosger,
no, it was my business SIM, so i have to organize the change with our IT department, that will need some more days.
The FP2 also gets hot without the Telekom SIM, so i am not sure if there is a connection.
You can use your SIM in the other slot? So it does not work in one of the 2 slots?
best regards,

1 Like

Hi Thomas,

apparently it seams to work in the other Slot for the Moment, but this is now only 4h, so let’s wait and see what happens…
best regards,

the SIM worked in the other Slot for 24 h - now it is dead, I will try and get a new one!

I have exactly the same problem with Telekom. FP2 killed the first SIM card then the next one worked fine for 2 weeks. Now it is killing that too - same symptoms as before… works after a reboot then fails. My vodafone.de card works just fine. This thread seems like an excellent description of the issue - did anyone get any response from Fairphone HQ?

Since I’m no sure if Fairphone are really aware of the problem, because it only affects users of some providers, I started investigating a bit about the problem.

In this article: http://alltech-reviews.de/oneplus-two-killt-telekom-sim-karten/ I found a statement of Telekom explaining the problem:

I already contacted Telekom and they told me the following: Their SIM cards use a feature called „MEC-Request“ (Mobile Equipment Change). Those requests contain things like activation, MMS-configuration, RDM-settings and more. The OnePlus cannot deal with these features and gives wrong feedback to the SIM card, so the SIM card tries it again and again, every 30 seconds, until the SIM cards memory flash cells break and the SIM becomes faulty. Here’s the German answer from Telekom: https://telekomhilft.telekom.de/t5/Handys-Datengeräte/AW-Defekte-Sim-Karte-beim-Oneplus-One/td-p/1589987/page/2

Affected providers:

  • Deutsche Telekom
  • Congstar
  • Klarmobile and Callmobile (only older SIMs, now they use the Vodafone network)
  • T-Mobile Austria

Affected SIM card types:

  • C/W2 Hybrid
  • C/W3 nano
  • C/W7

SIM cards that seem NOT to be affected:

  • V2 (Congstar, old)
  • B/V2 (Congstar)
  • C/V7 (Congstar, Deutsche Telekom)
  • C/T6 (Deutsche Telekom)
  • T-Mobile Austria say they have a compatible one, but I can’t find the version number

Other phones that are affected:

  • OnePlus One, One Plus Two, One Plus X
  • LG G2
  • Oppo Find 7a and N1
  • Xiaomi (Mi2S, Mi3 and Mi4)
  • others reported in the Congstar forum: Nokia Lumia 630 Dual-Sim, ZTE KIS PLUS, Lenovo Yoga 10 hd+ Tablet, Samsung Galaxy -GT18150, ZTE OPEN C, Yotaphone 2, InFocus, LG E-400, Phicomm Energy M E550

I also found the info that there is an update for the Oneplus Two that contains ‘Ultra SIM compatibility improvement’, so maybe there is a possibilty that Fairphone can fix the problem with a software update.

Meanwhile, I would recommend the clients of the affected providers to insist on getting a compatible replacement SIM (C/V7 or better C/T6).
When Congstar started to send out the C/V7, the complaints in the forum stopped, so there’s hope. I got mine on 9th March and had no problem so far. :sweat_smile:


This is very interesting information, I wonder if Fairphone is aware about this issue.
Maybe we should bring this to the attention of @keesj as maybe no one from the Fairphone staff knows about this thread.

1 Like

No, i haven’t got any response from fairphone

Hi there, I have the same problem with a german O2 SIM card. I don’t know how to access the SIM type information, though.

I don’t think that it’s the same problem. SIM cards sometimes simply die… The problem with these Telekom cards is that they have this special feature “MEC-Request” which seems to be the root of the problem (see my post above). As far as I know, O2 doesn’t use this problematic feature.

In the case of the Telekom SIMs, the type name is normally printed on the card.

Is there a difference between C/W2 and C/W2 Hybrid? I recived my FP2 on 25 February. On one card is printed C/W2 and on the other one C/V7. Both are still working :pray:

As far as I know, there’s no difference. The C/W2 is a hybrid mini/micro SIM. It’s well possible that yours will stop working in the nearer future. I got my FP2 on january 13th and the SIM died on march 7th. So it survived more or less two months. The days before it died it disconnected sometimes from the network and would only work again with a reboot.
Who’s your provider?

T-Mobile for both cards.

In order to get a better picture of how many people are affected, here’s a poll:


  • Congstar
  • Deutsche Telekom
  • T-Mobile Austria
  • Callmobile/Klarmobil
  • Other

0 voters

SIM card types

  • C/W2
  • C/W3
  • C/W7
  • C/V7
  • Don’t know

0 voters


No reply form FP yet.

My dead card is B/W7, but I voted for C/W7 as best guess choice.

Best regards