Sussex all-rounder Chris Jordan is to rejoin Surrey while team-mate Phil Salt is moving to Lancashire.
The England internationals will both join their new counties on three-year deals at the end of the season.
Salt, who turns 25 on Saturday, made his England ODI debut in July in the three-match series against Pakistan.
Jordan, 32, joined Sussex in 2013 after being released by Surrey and has gone on to play eight Tests, 34 ODIs and 65 Twenty20 internationals for England.
Barbados-born Jordan, who has become a key player in T20 competitions around the globe and for England, said his move to Sussex had helped him realise his dreams of playing international cricket.
“I’m very proud to have represented such a great club,” added the all-rounder, who was also part of the Southern Brave men’s side which won The Hundred earlier this month.
“I now feel it’s time for me to take on a new challenge.”
On returning to Surrey, where he will become T20 captain, he said: “I am extremely pleased to be returning to the place where it all started for me at the age of 17. I return having evolved not only as a cricketer but a person and I’m looking forward continuing that evolution.”
Meanwhile opening batter Salt said he would be leaving Hove with mixed emotions.
“The opportunity of playing for Lancashire, having spent much of my childhood in the north west, was something that I couldn’t turn down,” he told the Lancashire website.
Salt and Jordan will look to help Sussex to victory in the T20 Blast before moving on, after helping them reach Finals Day with victory over Yorkshire on Tuesday.