There are several reasons why it is a good idea to have a national auditing services company perform a contingency basis review of your utility bills for overcharges:

1. Cost savings: If the auditing company finds any overcharges on your bills, you may be able to recover some or all of the money that you were wrongly charged. This can lead to significant cost savings over time.
2. Accuracy: An auditing company has the expertise and resources to thoroughly review your bills and identify any errors or overcharges. This can provide you with peace of mind that you are paying the correct amount for your utilities.
3. Time-saving: Auditing your bills can be a time-consuming process, especially if you go back 36 months and continue reviewing for the next 36 months. By hiring a professional auditing company, you can save time and focus on other important tasks.
4. Ongoing support: If you choose to have the auditing company continue reviewing your bills for the next 36 months, you can have the peace of mind that someone is continuously monitoring your utility charges and ensuring that you are not being overcharged.
5. Expertise: Auditing companies have a team of trained professionals who are knowledgeable about utility billing and regulations. They can provide valuable insights and recommendations to help you optimize your energy usage and reduce your costs.

In conclusion, hiring a national auditing services company to perform a contingency basis review of your utility bills can potentially lead to cost savings, accuracy, time-saving, ongoing support, and expertise. It may be a worthwhile investment to consider.