NorthWestern Energy customers will see lower electric bills this month.

Annual cost and credit reports from NorthWestern show the utility recently collected about $2 million from residential customers.

Each year, NorthWestern projects what it expects to spend on fuel, along with sales and purchases of energy on the open market. The company will then refund 90% of what they overcharged customers if the figures are lower than expected.

According to regulators at the Public Service Commission, the average residential electricity customer will see a 5% decrease in their monthly bill, or about $6.00 less than normal.