INDIANAPOLIS (WISH) — Tens of thousands of AES Indiana customers have experiencing problems with their electricity bill.

The utility for all of Marion County and portions of surrounding counties blamed a tech upgrade.

AES tells I-Team 8 that 10% of its more than 500,000 customers are experiencing issues with their bills.

“Each issue is different. Over bill, or if you’re questioning the amount of a bill, if you have a different time frame on your bill that you’re seeing. We’ve had some bills that haven’t printed accurately. We’ve had some customers who’ve said they haven’t received a bill for the last two or three months,” said Kelly Young, a spokesperson for AES.

AES says the upgrade in technology is important.

“We were working with 25-year-old systems, and our customers need better, deserve better, and we want to give them something that can help them,” Young said.

So, how long will it take to iron out the kinks and get the system implemented with no problems?

“I wish I had an answer in terms of how long this will take. What I can tell you is that we have people that are working around the clock,” Young said.

AES says customers should call if they’ve experiencing any issues with their bills.

AES says it will not be shutting off power or leveling late fees to customers impacted by the problems.

The technology upgrade is being paid for with an expected rate increase that AES asked the state regulatory commission for last year. How much that increase will be is in negotiations with the Indiana Office of Utility Consumer Counselor.

Olivia Rivera, a spokesperson for the Indiana Office of Utility Consumer Counselor, said, “In October, we recommended a $19.1 million increase. That’s about a 1.2% increase. AES initially requested $134.2 million. That’s about an 8.4% increase. We ultimately were able to reach a settlement agreement that will result in a 4.6% increase. That’s about $72.9 million.”

The Indiana Utility Regulatory Commission will make its final decision on the rate increase in April. Whatever that increase, it will go into effect in July.