Press Association Sport understands Liverpool agreed several weeks ago to accept a fee of £15million, rising with various add-ons, to get the 24-year-old striker off their wage bill.
With the Hammers willing to pay the asking price for a player that cost £35million when joining the Reds from Newcastle in January 2011, the only barrier to the transfer is Carroll himself, who has spoken fondly of his season-long loan at Upton Park.
A major consideration for the England international, recently recalled to Roy Hodgson's squad, will be the implications of a pay cut at Upton Park. But with a World Cup just 12 months away, Carroll has to weigh up whether he would be better off playing regularly with little likelihood of first-team football under Liverpool boss Brendan Rodgers.
Despite only scoring seven goals at West Ham, the 6ft 3ins striker proved a popular signing and he admits he has enjoyed his time in London.
"I have enjoyed every minute of being here," he told whufc.com. "I have just tried to play my best in every match, score goals and keep myself fit once I got back from the injuries I had and then push on from there.
"I have worked hard to get myself back in the England squad, trying to play my best for West Ham, so I am really pleased about that.
"I just have to make sure I keep playing well to stay in there.
"I have had a great season here at West Ham, really enjoyed being part of a great set of lads in the team, with the staff around us and the fans.
"Everyone has been so welcoming to me and I have been over the moon to be here. This is a great club."