Originally Posted by
Often1
What is the routing. If an EU departure, you are entitled to a refund of 75% of the segment base fare, although no compensation.
The details really matter in these things and you show an EU location (at least until 2019).
Since you are departing UK you can claim compensation. Check this thread:
The 2017 BA compensation thread: Your guide to Regulation EC261/2004
But I would accept the voucher also which normally won’t remove your entitlement to EC261 compensation as well. The voucher is valuable for a space available upgrade.