E‑Verify is a government national identification system that employers currently use voluntarily to screen out unauthorized immigrant workers. Members of Congress want to make the program mandatory for all employers with the Legal Workforce Act, which has passed the House Judiciary Committee three times. This legislation would be the largest employer regulation in terms of scale in the history of the United States, applying to every single employer and every single worker in the country and also roping in several agencies to run it.

The system has already proven remarkably ineffective at its intended purpose—keeping unauthorized workers away from jobs. In fact, in many cases, it does the opposite—keeping authorized workers away from employment. While many have focused on how making it mandatory would increase the number of these errors, E‑Verify is already causing headaches and costing jobs for legal workers. In fact, from 2006 to 2016, legal workers had about 580,000 jobs held up due to E‑Verify errors, and of these, they lost roughly 130,000 jobs entirely due to E‑Verify mistakes.

Here’s how E‑Verify catches innocent people. The system checks information all workers must provide on their I‑9 forms against the databases of either the Department of Homeland Security (DHS) for legal immigrants or the Social Security Administration (SSA) for U.S. citizens. If the system fails to verify this information, it will issue a “tentative nonconfirmation” (TNC). People who receive a TNC must challenge it within two weeks or it turns into a “final nonconfirmation” (FNC), and the employer must fire them.

Legal workers can receive an erroneous TNC for a variety of reasons. Employers may have put their information into the system incorrectly. This is especially common for hyphenated names or individuals with multiple last names. It can also happen if someone changes their name, but SSA or DHS has failed to update their entry in the database. Errors can also occur when SSA or DHS employees enter a person’s information into the database.

Whatever the case, the employee has an affirmative duty to fix the issue. They must formally contest the error. If they are a citizen, they need to physically visit a Social Security Administration office to figure out the problem. If they are a legal foreign worker, they need to go to DHS. This process can take months because the worker has no idea what the problem is. In 2012, it took more than 8 days to resolve a TNC for more than a third of all legal workers who received one.

Unfortunately, U.S. Citizenship and Immigration Services (USCIS) data fails to report in more detail how long these took to resolve, which could potentially have taken months. For workers who need to submit a Privacy Act request to obtain their records, it can take more than three months even to obtain a response, let alone fix the underlying problem. As the Table below highlights, from 2006 to 2016, legal workers had to overcome 450,039 tentative nonconfirmations. Under the Legal Workforce Act, employers could condition employment based on an E‑Verify confirmation, meaning all of these workers would lose weeks or months of wages. If the job was temporary, they could lose it entirely.

Table: E‑Verify Cases and Errors, 2006 to 2016

Sources: Total cases (2006–2014): U.S. Citizenship and Immigration Services, “E‑Verify History and Milestones,” January 19, 2017. TNC share overcome (2011–2016): U.S. Citizenship and Immigration Services (USCIS), “E‑Verify Program Statistics – Performance.” USCIS archived pages. E‑Verify Erroneous TNC and FNC rates (2006–2010): Westat, “Evaluation of the Accuracy of E‑Verify Findings,” July 2012. (Note FNC error rate in Westat expressed in terms of share of FNCs.)

But that’s not all. Some legal workers lose the opportunity for a job completely due to E‑Verify. Legal workers can receive a FNC that results in them being permanently fired for two reasons. The first is that the person decides not to bother challenging the TNC. This accounted for roughly 17 percent of all erroneous FNCs, according to a study commissioned by USCIS. The other much more common reason is that employers neglect to tell them that they received a TNC. This accounted for 83 percent of erroneous FNCs.

The USCIS-commissioned study provides the erroneous TNC rates since 2006, but only provides the erroneous FNC rate for 2009. As the Table shows, the TNC error rate has improved over time, so this estimate assumes that FNC accuracy improved at the same rate as TNC accuracy. If this held true, then nearly 130,000 legal workers were wrongfully issued TNCs and then subject to wrongful FNCs that likely cost them their jobs.

Proponents of the Legal Workforce Act tout E‑Verify’s accuracy, but the fact that the program works as intended for 99.8 percent of workers is less impressive when it is imposed on such a large population. The 0.2 percent equaled more than 62,000 people in 2016 alone. If all employers—big and small, with or without many foreign-born workers—were required to use it, the errors would grow. Indeed, if every new hire went through the system in 2017, at least 120,000 legal workers would have been wrongfully ensnared in the system in that one year alone, implying more than a million errors per decade.

E‑Verify is a big government regulation that fails to prevent illegal immigration and harms U.S. workers. A better plan to eliminate illegal immigration would be to make hiring foreign workers legal. Legalize the current unauthorized immigrants and create a large year-round guest worker program. Government regulation has failed time and time again. America should try the free market for a change.