Just wrapped up what I thought was a straightforward audit for a small manufacturing client in Phoenix. Somehow I completely missed that Arizona Public Service was applying the wrong gas transportation tariff (GT-2 instead of GT-1) for over 14 months. The client was paying an extra $340/month in transportation charges. I'm embarrassed I didn't catch this initially - the rate codes are right there on page 2 of every bill. Anyone else have similar experiences when starting out? How do you ensure you're catching these seemingly obvious errors?
Missed a major error in gas tariff calculation - learning experience
Don't beat yourself up too much - we've all been there! Gas tariffs can be tricky, especially when utilities use similar rate codes. I missed a similar issue with Atmos Energy in Georgia last year. Now I always create a checklist that includes verifying the tariff code matches the customer's usage profile and service characteristics. Also helps to have the utility's tariff schedule printed out for reference.
Welcome to the learning curve! Your experience is actually quite common, and the fact that you're reflecting on it shows you're developing the right mindset. I've been doing this for years and still occasionally catch myself making assumptions. For gas audits specifically, I recommend always verifying: 1) Service classification matches actual usage, 2) Transportation vs commodity charges are properly separated, 3) Interruptible vs firm service designation is correct. The $340/month you found will add up to significant savings for your client - that's a win in my book!