Eventually such individuals are removed from voter rolls, but there can be a lag time of several years, and in the meantime more registrations become out of date.

That’s because state and local election organizers are not always able to track when registered voters move out of state or if they die outside of Massachusetts.

Massachusetts voter rolls list a record 4.5 million registrations, but an untold number — potentially as high as 1 million registrations — should no longer be on the books.

State officials said they do not believe any of the discrepancies are nefarious in nature or signs of voter fraud.


But Secretary of State William Galvin, whose office maintains state voter records, also said he has been advocating for Massachusetts to join the Electronic Registration Information Center, or ERIC, a consortium of states that have agreed to share voter registration and drivers license data to keep more accurate voter rolls.

ERIC began in May 2012 with seven states and now features 20 states, as well as Washington D.C., which pay annual membership dues for access to software as well as technical and administrative assistance.

“We’ve been pushing for it for a couple of years,” said Galvin.

State Representative Jay R. Kaufman has filed a bill that would have Massachusetts join ERIC and would also allow eligible voters to be registered automatically. He said joining ERIC could help clear up inaccuracies in the state’s database, including from voters who moved out of state or died in another state.

More accurate records would reduce the potential for fraud and abuse, Kaufman said. Studies examining voter fraud have found a few minor cases, none of them serious enough to affect the outcome of an election.

Improved registration could also lower costs on inefficiencies like notices sent to old addresses and cut down on the hassle that voters and election officials experience.


“Local clerks and voters would have an easier time with a more technologically advanced system, and that’s good for democracy and how we spend taxpayers’ money,” said Kaufman.

John Lindback, ERIC’s executive director, said the system can also be helpful in removing out-of-date registrations from voters who have moved within state — a problem that, although less likely to inflate voter rolls, is far more common than out-of-state moves or deaths but can be just as problematic for voters and local officials on Election Day.

The state Republican Party said it supports efforts to improve the accuracy of voter records.

“While we have faith in the integrity of the voting system in Massachusetts, the MassGOP believes election officials should work to ensure voter rolls are accurate and that only eligible citizens are able to cast ballots on Election Day.” MassGOP executive director Brian Wynne said in a statement.

Michael Murray, deputy executive director of the Massachusetts Democratic Party, said that whenever a person moves or dies, there is going to be some “natural lag in getting that information back to the [local] clerks,” and election officials. “But there’s no evidence of anyone committing any sort of voter fraud or anything like that.”

Massachusetts officials said there’s no way to know exactly how many voters are registered who shouldn’t be.

The number may be significant.

In November 2014, the US Census Bureau estimated that just 3.25 million people were registered to vote in Massachusetts. At that same time, the state said it had 4.3 million registrations.


Another way to look at it — if the state’s current estimate of 4.5 million registrations were accurate, it would mean that about 92 percent of people the Census says are eligible to register in Massachusetts are signed up.

The Census data, to be sure, are based on surveys and samples, and come with margins of error and notes that their counts may differ from official voter records. But none of that would entirely explain the large gap.

Galvin outlined one other potential factor: Massachusetts’ many college students.

Elections tend to happen when students are living on or near campus, and many students, including some from out of state, register to vote in Massachusetts, making them part of the state’s official count of registrants, he explained. But population estimates often don’t capture the true total number of college students.

There is already a process by which out-of-date registrations are eventually removed from voter rolls.

The state labels voters “inactive” if they do not respond to annual censuses that each city and town in the state conducts.

Galvin said that of the 4,534,974 voters registered as of Oct. 19, the last day people could register for the upcoming election, 540,510 of them, or nearly 12 percent, were considered “inactive voters.”

Inactive voters can still vote, but they have to clear extra hurdles that don’t apply to active voters.


When checking in to vote, inactives are asked to fill out and sign a form saying where they live and to present proof of their residency.

But if an inactive voter fails to cast a ballot for four years — or in two consecutive biennial state elections — and does not take any other step to affirm their residency with election officials, they will be removed from voter rolls completely.

Galvin said federal law requires inactive voters to be kept for that long.

Inaccurate, out-of-date voter rolls are far from unique to Massachusetts. Many other states deal with similar issues, studies have found.

The Pew Center on the States in 2012 issued a report highlighting how voter registration systems have failed to keep pace with technological improvements and “are plagued with errors and inefficiencies that waste taxpayer dollars, undermine voter confidence, and fuel partisan disputes over the integrity of our elections.”

The report said that, at the time, about 24 million, or one in every eight, voter registrations nationwide were no longer valid or “significantly inaccurate.” That included more than 1.8 deceased individuals listed as voters and 2.75 million people with registrations in more than one state.

The Providence Journal this week reported that voter rolls across all six New England states appear to contain many more registrations than Census surveys say they should.

The Journal estimated that Massachusetts had the highest number of extra voters of any New England state in raw figures and the third highest as a percent of voters.


The 2016 election The newspaper reported that the state that appeared to have the lowest proportion of excess voters regionwide was Connecticut, which joined ERIC in 2014.

Matt Rocheleau can be reached at matthew.rocheleau@globe.com.