An offer of proof—also known as an informal bill of exception—is a procedure available during trial for the presentation of evidence the trial court has excluded. An offer of proof is made outside of the jury’s presence and often after the judge has sustained an objection to the admissibility of the evidence.

A bill of exception—also known as a formal bill of exception—is a procedure that allows a party to complain on appeal about evidence that would not otherwise appear in the trial record (because there was no offer of proof made at trial) by detailing the evidence (testimony, etc.) that would have been offered if the trial court had allowed it.

In Georgia, an offer of proof is a procedural mechanism used during a trial when the court excludes evidence. This process allows the attorney to create a record of what the evidence would have shown, had it been admitted, by presenting it outside the jury's presence, typically after an objection has been sustained. The purpose of an offer of proof is to preserve the excluded evidence for appellate review, ensuring that the appellate court is aware of the nature and substance of the excluded evidence when considering whether the trial court's decision to exclude it was correct. On the other hand, a formal bill of exception, which is less commonly used under modern procedural rules, serves a similar purpose. It allows a party to detail evidence that was not put into the record at trial due to the lack of an offer of proof. This procedure ensures that the appellate court can review decisions about evidence that was never formally offered. Both mechanisms are designed to protect the rights of the parties by preserving issues for appeal regarding the admissibility of evidence.