public transport in Berlin

Here are a few hints, I looked up today, and that may be valid for a couple of weeks or months.
No warranties at all!!!
In case of doubt or for further information, pls refer to the BVG Tickets+Fares home page: www.bvg.de/index.php/en/ / Tickets+Fares !

• There are 3 "tariff zones" in Berlin. For simplicity assume, you will always only be traveling within zones A and B aka "A+B" aka "AB".

• Single trip tickets "A+B" cost EUR 2.10. 4-trip tickets (or any kind of "n-trip tickets") are not cheaper than single trip tickets, but you have less hastle with 4-trip tickets.

• Single trip tickets are valid for 2 hours, they are strictly "one direction only", at least certainly no loops involved.

• A "day pass Berlin AB" costs EUR 6.10, obviously it's worth going for a day pass, if you think, you would need at least 3 tickets per day.

• There is a "Berlin WelcomeCard (5 days)" (basically a 5-days-ticket to "Berlin AB" plus a few vouchers, whose usefullness I cannot assign a proper value to so far) for EUR 29.90. (There exist a few variations of that as well ..., have a look here, if you want so!)

• A simple regular 7-days-pass costs EUR 26.20. (I rather recommend that one, if you don't stay longer than 5 days.)

• I also recommend you get tickets at a vending machine or at "info points" like at Tegel Airport, not on the bus.
• Ticket machines usually accept cash and  Maestro cards, no credit cards at all.