You can use MPI-INF telephones for making private calls. For this purpose you need a personal private phone code which can be obtained from Roxane Wetzel (Tel. +49 681 9325 702, MPI-INF room 005a).
Dial this code before the phone number; a unit is charged with 0.0664 Euros. The billing period covers three months and payment should be settled in cash with Sarah Scherer ( MPI-INF room 003, phone +49 681 9325 705). A booklet of rates for international calls is enclosed with the folder you receive upon arrival. For the lowest phone tariffs, use the service of private companies (see www.teltarif.de or www.tarife-check.de) with discounts ranging from 30 to 70 percent. Unfortunately, due to the special features of our phone system, this is not possible when using MPI phones. So don't use bargain prefix numbers when making phone calls from the MPI-INF. If you try to do so, you may either not get a connection at all, or it may be the case that you in fact pay the normal (expensive) rate, although you think that you are using the cheaper prefix.
A coin-operated public phone is located next to room 017, ground floor. Other pay phones are located in front of building E1.1 (operated by phone cards) and outside building A5.3 in the middle of campus. Phone cards can be purchased at post offices, stationery shops, or major department stores. To reverse phone charges (collect call), please dial the operator at 0100, who puts you through to any country and number you wish.