Czech Republic

O2
NOTE Some of this information seems out of date. I will mark new information on O2's czech website as NEW and potentially out of date information as OLD. Regard NEW as untested (but publicly published) information. I will update when I have tested this out.

O2 stores will sell you a SIM card for around 300kr. These are all PIN protected and the PIN is on the card you press the SIM out of.

OLD Once the SIM is in your device it will activate itself. You then need to select the Internet tariff by texting "INT" to 999111. This will activate within 24hrs and then you will be charged about 40kr per week for data access. Before this activates you will be charged 20kr every ten minutes you use data! I believe you can make calls and text from this tariff but obviously at a premium rate since the idea is that this tariff is aimed at data users.

Settings
NEW To get your phone settings, text "IVMNASTAV" to 999555. You will receive an SMS shortly afterwards with details. If asked for a PIN code, use 12345 or 1234.

NEW To choose "start" plan, text "IVM1" to 999111.

NEW To choose "basic" plan, text "IVM2" to 999111.

NEW To deactivate your active plan, text "DIVM" to 999111. This is useful if you leave the country and intend to return, where it can be reactivated.

NEW MMS Settings: APN: "MMS", MMSC: "http://mms.o2active.cz:8002", MMS proxy: "160.218.160.218:8080", Max Size MMS "307200"

NEW Mobile data settings: APN: "internet"

Default data rate
GPRS, EDGE, UMTS, HSDPA

Data feature packs

 * NEW default-not-on-a-plan plan, per day 30CZK/day, FIRST HOUR 15CZK, 30MB acceptable use (full data)
 * NEW "start" plan, 40CZK/week, 150MB/month acceptable use (email, IM and web)-week FPU approximately 37 MB
 * NEW "basic" plan, 75CZK/week, 500MB/month acceptable use (full data) - week FPU approximately 125 MB
 * OLD 40kr per week

NEW However, it is also stated that "After reaching your download limit (FUP), your speed slows down to 16 kb/s. You are not charged for data transferred above your limit.". Maybe this means you can then continue to use free data at a slower speed?

NEW There are comments about the type of data that can be used on these plans implying that only certain types of traffic can be used, specifically on the "start" plan. I don't know if this is enforced. Where I've noted "full data" there is specific mention of youtube and high-traffic applications.

Availability

 * O2 stores and most supermarkets

SIM sizes

 * Standard SIM available for 300kr. This is suitable for cutting to mini-SIM size which works fine in an iPad or iPhone 4.

Tethering

 * No (It's the only provider in Czech republic with no tethering; Vodafone and T-Mobile YES)

Vodafone
rates updated 02/2014, valid until 05/2014

czech mobile plans www.vodafone.cz/en/phones-plans/notebook-and-tablet/

A repaid Vodafone SIM costs 300kr and comes with 300kr of credit. The default PIN is 1234 and the SIM is automatically activated when placed in your phone. You can sign up for a data option when you buy the SIM but be sure not to use data until you get a confirmation SMS. You will get 9 SMS at all. The SMS will begin with "Dobry den, prave jste zahajili vyuzivani sluzby Internet v mobilu na den." Once a data plan is activated it remains in effect for one month and is renewed automatically until you cancel it yourself. If you do not have enough credit at the time of renewal, your rate will automatically change to the basic Vodafone mobile Internet on that day. The daily rate renews automatically every day on the same principal.

Technical details
APN: "internet"

Frequencies
GPRS, EDGE, UMTS, HSDPA

Data feature packs

 * 25kr for 25MB per day
 * 49kr for 60MB for 1 week
 * 75kr for 500MB for 48h
 * 178kr for 250MB per month
 * 249kr for 500MB per month
 * 399kr for 1.5GB per month
 * 519kr for 4GB per month
 * 999kr for unlimited per month.

Availability

 * Vodafone stores, most supermarkets, post offices (Česká Pošta)

SIM sizes

 * Comes as Universal Sim, so both Standard and Micro SIM are supported

Tethering

 * Yes

T-Mobile
I had good success in September 2012 with T-Mobile CZ. The friendly staff in the T-Mobile shop in the Fénix mall in Prague Vysočany sold me a Twist (prepaid) SIM card for CZK 200 with a balance of CZK 200 on it. The card had a PIN that was printed on the card holder along with the other codes. It actually had free Internet usage included, though I think this is a time-limited promotion; the normal "occasional use" Internet fee for prepaid is CZK 24 per day. There is a "fair use policy" that limits the speed once the daily usage exceeds 25MB.



SIM sizes
The Twist SIM that I bought in September 2012 has the classical format, but has a cut-out line suggesting that it can be converted to Micro-SIM format (though possibly not back?).

Tethering

 * Yes

COOP Mobile
Prepaid SIM card for CZK 200 with a balance of CZK 200 on it.

http://www.coopmobil.cz/tarify/predplacena-karta/

The tariff is CZK 20,- for 25MB per day. the next 25MB is on the same CZK 20,-

You can buy also some monthlyy fixed tariff on 300MB at CZK 159,- with additional 100MB on CZK 60,- or 1GB on CZK 399,-

http://www.coopmobil.cz/sluzby/internet/