Massachusetts cities and towns spent an estimated $720,000 to comply with the state’s new early voting law, and the state auditor says the government should be on the hook for the tab.

When Massachusetts introduced early voting for the November general election, the state required all cities and towns to meet certain requirements: offering at least one poll location to be open during business hours for 12 days leading up to Election Day, and offer early voting by mail. Auditor Suzanne Bump said the costs of providing these new services added up to an unfunded mandate.

“The early voting law certainly is to be regarded a success. It did, however, mandate new procedures for clerks. Some of these should be paid for by the state, not municipalities,” she said.

State law gives cities and towns recourse when faced with a potential unfunded mandate — they can petition the state auditor to issue a determination. If it is determined an unfunded mandate exists, they can seek exemption from the courts in the absence of funding.

Woburn and Oxford petitioned Bump, who determined some of the early voting costs should be paid for by the state — about $5,400 for Woburn and $1,500 for Oxford.

Bump queried Massachusetts municipalities to find out what the expenses were, making a distinction between required and optional costs.

Some cities and towns went beyond the law and opted to offer extended early voting hours, or early voting at more than one location. Costs related to personnel for optional early voting locations or extended evening and weekend hours, office supplies, newspaper advertising, police personnel at early voting locations topped $1.2 million based on figures from the 280 communities where data were available. But since extended hours were not required by law, Bump said, associated costs should be paid by the individual cities and towns.

More than a million people — about 22 percent of Massachusetts’ registered voters — voted early.

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Lawmakers did offer some grant money to cities and towns when the passed the law in 2014, but Bump said it was insufficient.