Is to "tell off" a particularly British expression?

Solution 1:

Tell us off is an American idiom. However it is much less frequently used in American literature than in British literature.

As noted by StoneyB, young children in the US would be very unlikely to use the phrase. In addition to his yell at us, young children might say

We'll get in trouble
or
We're gonna get it

Solution 2:

No, it's colloquial American English as well.

A specifically British synonym would be 'to scold', or possibly (and more crudely) 'to bollock'.

Solution 3:

The truth seems to have been arrived at in comments posted by myself and StoneyB, but here it is as an answer. Firstly, note this chart of British usage for "told off for not"...

...where if you follow the link and switch to the American corpus, you'll see that even though this indexes far more books, there aren't even enough results to graph.

I specifically included "not" in the search string because that ensures almost every instance will be for OP's "scolded" sense. Without that, the results would be swamped by contexts where "to tell off" means either to count off, or assign responsibility (both of which senses are "dated", if not archaic, but still occur often enough to obscure what we're interested in here).

If you leaf through the citations in that link, you'll soon notice that many if not most of them involve young people. It's essentially a post-war British children's slang usage, so the answer to OP's question is: No - it's not a normal, acceptable American expression.

Although I'm not American, and therefore probably shouldn't pronounce on whether an expression is familiar to Americans, I think it's worth pointing out that (British) "Mum told me off" gets over 300 hits in Google Books, whereas (American) "Mom told me off" gets none at all.