Sales tax on exempt usage: utility billing error

Sales tax on exempt usage

Sales or utility tax is billed on electricity or gas used in manufacturing or processing that state law exempts once predominant use is documented.

How often we find it

Found at roughly 1 in 5 manufacturing and food processing sites we audit

Typical impact

The full state and local tax rate on qualifying usage, often 4% to 8% of the bill

Many states that tax utility service exempt electricity, natural gas or water consumed directly in manufacturing, processing, agriculture or similar activities. The rules are state-specific. In some states, a meter qualifies for a full exemption once more than half of its usage is consumed in exempt activity; this is the predominant use test. Other states exempt only the qualifying percentage, and a few require the percentage to be recertified every few years. In nearly all cases the utility will not stop charging tax until the customer files an exemption certificate, usually supported by a predominant use study: an engineering inventory of the equipment on each meter, its rated load and operating hours, and the share of consumption that goes to exempt versus non-exempt uses such as offices and lighting. Sites that never filed, sites that added meters after filing, and sites whose certificate lapsed keep paying tax they do not owe. Refunds for past periods are generally claimed from the state tax agency, or through the utility, within the state's refund statute of limitations.

How it happens

The site never filed an exemption certificate with the utility, so tax has been charged since service began.
A new meter, account or service was added after the original filing and was never covered.
The certificate expired or required recertification that was missed.
A utility billing migration dropped the exemption flag from the account.
Only the state tax was exempted while a local tax with its own exemption was still billed.

How to detect it

List every tax line on every bill for production sites and compare it to the exemption certificates on file with each utility.
Inventory equipment by meter and estimate the share of consumption used in exempt activity.
Check the state's rule: full exemption above a predominant use threshold, or a pro-rata percentage.
Confirm that local taxes, franchise fees and gross receipts surcharges are treated under their own rules.

Evidence the utility will accept

A predominant use study signed by a qualified engineer, with equipment schedules and load calculations
The state exemption certificate filed with the utility, and its acceptance date
Bills for the refund period showing the tax lines
Production records showing the site's manufacturing or processing activity

Recovering the overcharge

We commission or update the predominant use study, file the exemption certificate with the utility so tax stops on the next bill, and prepare the refund claim for prior periods. Depending on the state, the refund is claimed from the state tax agency directly or through the utility, and the look-back is limited by the state's refund statute of limitations, commonly 3 to 4 years. Claims need the study, bills and proof of payment.

Questions we get asked

No. Rules differ in what qualifies, whether the exemption is all-or-nothing or pro-rata, and which taxes it covers. We confirm the rule in each state before quoting a recovery figure.

Usually a licensed engineer who inventories equipment by meter. Trace Global's tariff research team prepares studies and coordinates sign-off where the state requires a specific credential.

It depends on the state. Some route refunds through the utility, which then recovers from the state; others require the customer to claim directly from the tax agency.