Proper identification is a fundamental social calling card, necessary for anyone looking for a job, housing, government services, or health care.

But countless numbers of people nationwide — particularly the homeless, immigrants, and the impoverished — don't have basic identification cards to verify who they are. Birth certificates and other supporting documents needed to apply for government ID cards can cost as much as $50 each, beyond the means of some low-income people. And then they have to come up with the cost of the ID card itself.

"It really is a huge barrier for people," said Eric Tars, senior attorney at the National Law Center on Homelessness & Poverty.

Tars said eliminating fees for photo IDs is one of the best steps states can take to help people get on their feet. Philadelphia is the poorest big city in the country and the only large city where median household income fell from 2016 to 2017.

Waiving ID fees requires changes to state law in Pennsylvania and New Jersey, although Gov. Wolf has the authority to waive fees for copies of birth certificates. He has already waived these fees for people addicted to opioids. Last year, New Jersey passed new laws to waive application fees for both IDs and birth certificates for people in homeless shelters.

Advocates have been working to get similar laws passed in Pennsylvania. They've been lobbying state lawmakers to introduce legislation. A PennDot spokesperson said the Wolf administration supports ID fee waivers for homeless Pennsylvanians. Pennsylvania currently issues free IDs only if people cannot pass a test needed for driver's licenses.

At least eight states issue free or discounted IDs to low-income or homeless residents and at least 10 states waive ID fees for seniors. New York issues free IDs to low-income seniors.

State IDs typically expire every four to eight years.

Adam Bruckner, founder of Philly Restart, which helps men and women who can't afford to get IDs, said his organization pays a portion of the ID fee for its clients. Philly Restart's checks are good for only two weeks, however, and he said it's not uncommon for clients to be left holding expired checks that would have covered about half the $30.50 fee.

"A lot of times, if we don't pay for the full amount, they're unable to come up with the rest," Bruckner said. Some of his clients panhandle not only for food, but also to scrape together money for an ID.

"It's a pretty unbelievable thing for a passerby to hear," he said.

At least five states — Georgia, Indiana, Missouri, Tennessee, and Wisconsin — offer free IDs that residents can only use to vote. South Carolina and North Dakota, two of the states that require residents to have ID to vote, passed laws in 2011 to give free identification cards to all adults.

Below is a more detailed comparison of these two states and New Jersey and Pennsylvania.

How much do non-driver photo state IDs cost?

New Jersey: $24 for four-year card

Pennsylvania: $30.50 for four-year card

South Carolina: free for 17 and older for five-year card; $5 for children 5-16

North Dakota: free for 18 and older for eight-year card; $8 for minors

Where do the fees go?

New Jersey: $6 of each card pays for the digital photo. About $7 goes to the New Jersey Motor Vehicle Commission's operating budget. About $11 goes to the Treasury Department's general fund.

Pennsylvania: $9.50 covers the cost of the photo. About $16 goes to the state's Public Transportation Trust Fund. About $5 goes to the Multimodal Transportation Fund, which supports public transit and other non-highway and bridge means of transportation.

South Carolina: The $5 fee for children goes to the Department of Transportation's highway fund for roads that are not qualified to receive federal funds. The state legislature pays for the cards.

North Dakota: The $8 fee for children goes to the Department of Transportation toward the cost of the cards. The state pays for the remaining cost.

Who can get an ID?

New Jersey: Residents 14 years old and up

Pennsylvania: Residents 10 years old and up

South Carolina: Residents 5 years old and up

North Dakota: Any resident

Roughly how many residents have non-driver photo IDs?

New Jersey: 596,000

Pennsylvania: 1.6 million

South Carolina: 560,000

North Dakota: 47,000