Under Florida Rules of Civil Procedure a Defendant may bring a Cross Claim against another Defendant. If the other defendant you wish to cross claim has been served by the Plaintiff and has appeared in the case such that court has legally taken jurisdiction over them, then you do not need to issue a summons for your cross claim. If they have not been served then generally you will need to issue summons and perfect service on that defendant pursuant to the Rules of Civil Procedure. The scope of a cross claim can be broad. There is no bright line for a judge to deny a cross claim and force you to bring a sperate claims against the party you seek redress. Most of the time the matter will be allowed to proceed with a cross claim if the court does not feel that to do so would delay or prejudice any other party. The above is a general response and as with any litigation the facts and applicable law may be different. This answer is given solely as general information and is not a substitute for a legal consultation, nor does it create an attorney-client relationship between you and either the writer or his law firm.