Surrey cancelled Kevin Pietersen's registration on Wednesday, removing the ECB's ability to take disciplinary action over his forthcoming autobiography.
His contract at The Oval ended on August 30, which in theory leaves the former England batsman free to negotiate a deal with another club.
However, he is scheduled to have further talks with Surrey at the end of the year about a possible return next summer.
The move by Surrey was prompted by fears the ECB could use his registration as a means to punish him for the contents of his book, to be published next Thursday.
As a registered county player, Pietersen would have to seek ECB permission to play in the Big Bash in Australia this winter and the Indian Premier League.
There were concerns the Board could refuse consent, in response to any book revelations about what happened last winter in Australia and the end of his time as an England player.