Getting British pounds upon arrival at Heathrow
 

Is it as easy to use plastic in an ATM at Heathrow to withdraw pounds as it is in other European destinations? Or should I buy pounds from my bank and have them with me when we arrive?
Thank you in advance for your answer!

Plenty of ATMs at Heathrow.

If you're taking the tube from T1/2/3, I know for sure there's a Barclays ATM right before you enter the tube station. That's where I get my £ everytime I arrive into Heathrow, before I get on the tube.

Yes, it is as easy to use plastic in an ATM at Heathrow as it is in other European destinations.

I second yk's suggestion. When we arrived in London, the ATMs on the main concourse of the terminal had very long lines, and some were out of cash. No lines at the Barclays near the tube entrance.

I am surprised you'd think LHR/London and/or the UK in general is more backward than other countries . . . .

LHR has lots of cash machines, and there are more ATMs per block in London than in most US cities (they are everywhere)