The two-time Holland international will travel to Merseyside over the next few hours for a medical, with the deal expected to be announced tomorrow afternoon.
"It's a very nice step to move to the Premier League. For me, my qualities can be fully expressed there," he told RTV Rijnmond. "Everton have always been a good club to join. It's nice that they have come in for me. It is earlier than I expected, but I am definitely happy to join them.
"I have only played for one-and-a-half years at Twente so the fact that Everton have come in for me so quickly shows the confidence they have in me. That feels good."
Fer is said to have cost the Toffees around £8m.