The phrase is informal and often implies a mistake is not very severe or can be fixed.

Not Severe

Use 'muck up' in casual situations or conversations, not in formal writing or speeches.

Casual Contexts

Commonly used by someone admitting their own mistake in a humble or joking manner.

Can describe situations where getting dirty is part of fun or work, not necessarily negative.

Sometimes getting things messy happens on purpose, like children playing or artists creating.

Indicates that the mess made is temporary and can often be cleaned up.