The fees range from $5 for schools through to $50 for major sports events.
This week, there were at least 33 primary, secondary and intermediate schools forced into lockdown after malicious calls were made to principals threatening live bombs in schoolyards across the country.
One call targeted Napier's Tamatea High School.
In each case, the call appears to have been made locally using voice over internet technology (VoIP) that converts international calls into local phone calls.
Mr Ayers said it was important for the loophole to be closed at a government level.
"What's going on at the moment is so harmful to society that there needs to be a regulatory response to it to either make it impossible to make voice-over-IP calls out of or into New Zealand, or at least strengthen the protection so if they do things they shouldn't they can be stopped."
He said the sudden explosion of hoax threats could have been requested from local school children or simply the group spreading its reach from across the Tasman, where it had caused a headache for authorities in recent weeks.
"What we don't know is whether it's spreading because this group is bored and they just want to find more targets or it's spreading because kids at various places, particularly schools, are contacting the group and inviting them to do it to their school because they think it would be fun to get them out of class."