Originally Posted by
athome
Strongly depends on the reason. And its 4 hours, not 3.
As any of the EU261 threads will tell you the threshold for compensation is 3 hours for long-haul flights not 4 — a delay of 3–4 hours just means 300EUR instead of 600EUR. Also the reason for this delay seems pretty clear-cut — delayed inbound from MUC
Either way if OP doesn't write in for compensation they won't get any so no harm in doing so, no?