Take plenty of cash to Munich else you'll be looking for cash machines.
In short, yes, cash is certainly king in Munich.
In fact, there are many places where you are not going to be able to use credit cards so cash is required.
Even some larger establishments do not accept cash.
Table of contents
Do you need cash for the Public Transport?
No. You buy tickets from machines at the main stations and stops.
Some of these will accept cash, whilst they all seem to accept credit cards.
Where accepts cards in Munich?
Don't depend on cards in the market - make sure you have cash.
Not many places.
Looking at my credit card statement it looks like Munich was a cheap holiday, it wasn't.
Entry tickets bought on the coach to Neuschwannstein Castle (read more) were on card, but the on some trips they insist on cash (it's clear when you book).
A few shops did take cards, but they mostly expected cash.
Some of the large restaurants take cards readily, but have cash ready just in case.
Do you need cash for the Oktoberfest?
Oktoberfest is cash only, but there are cash machines when you've spent up.
If you are visiting the Oktoberfest then credit cards will not be accepted.
There are plenty of cash machines, but every beer tent, fairground ride, souvenir seller and gingerbread stall will want cash.
You can get it 'out of the wall' if you need to, but credit cards aren't going to help you.
And if you are buying a few mass weissbiers, chicken and a few fairground rides then that's plenty of cash.
What currency do I need in Munich?
Euros...
That simple, you will just need Euros and plenty of them in Munich.
A credit card for those one off just in case moments, but Euros are your biggest friend.
You'll find notes for €5, €10, €20, €50 and more with coins from 1c to 2 Euros.