Green Card - living abroad question

My husband has a green card. He's moved back to the UK while I wait here a few months more in the US.  What's the correct way to handle his green card? He's back visiting me every 2-3 months or me going there. 

From what I'm reading he's ok to use the green card as he is coming back frequently and we still have a residence here. But as he has no intentions to make the US a permanent home he may have a hassle at the border and need an additional permit.

Anyone with any experience with this? Wondering if we should cancel the green card now or wait until I'm settled back in the UK.

You don't need to cancel the green card - it will just expire once he is out of the US for more than one year. Easy.

For now what you are doing is technically fine.

That's not true.

If he's giving up permanent resident status in the US, he needs to return his green card, along with form I-407 -- otherwise he will run into trouble. Maybe not immediately, but certainly eventually. We once wound up behind a couple in Dublin who hadn't properly surrendered the green card, and they were hauled off to the Frightening Little Room (as were we) so I had a good earful -- it was not pleasant.

I have read there can be trouble without properly surrendering the green card. Think as he is coming back and forth a lot hopefully it won't be an issue but once I am back settled in the UK he should properly surrender it.