There are procedural requirements governing this process. It costs NZ$500 to file a petition asking for a referendum with the Clerk of the House of Representatives. The Clerk formally determines the wording of the question, which may be quite different from the original. Once the Clerk receives the completed petition, the number of signatures is initially counted, followed by sample groups of signatures being taken and the signatories' names and addresses checked against the electoral roll. The sampling of signatures is used to estimate the number of valid signatures for the whole petition with confidence, and if the lower confidence interval is more than ten percent of the electoral roll, the petition is presented to the House of Representatives.