There are three possible answers to your question.
First, review your bylaws or other governing documents. Does it address the issue? Most church governing documents do not address the retention of ballots, but be sure to confirm this.
Second, if the bylaws do not address ballot retention, check out the state nonprofit corporation law under which the church is incorporated. Most state nonprofit corporation laws do not address this issue.
Third, in most cases, a church’s bylaws and applicable nonprofit corporation law will not address ballot retention. In such a case, check your governing parliamentary authority for guidance. The current and newly revised 11th edition to Robert’s Rules Newly Revised addresses this issue as follows:
After completion of an election or balloting on a motion, unless the voting body directs otherwise, the tellers place the ballots and tally sheets in the custody of the secretary, who keeps them under seal until the time within which a recount may be ordered expires, and then destroys them.
Robert’s Rules Newly Revised notes that a recount may be ordered by the voting body through a majority vote at the same session at which the voting result was announced, or at the next regular session if that session is held within a quarterly time interval. A recount also may be ordered at a special session called for that purpose if held within a quarterly time interval of the session at which the voting result was announced and before the next regular session.
For more help with church board leadership matters, check out the 4-Hour Legal Training Program for Church Boards.