Pre-employment screening is used to verify the accuracy of an applicant's claims as well as to discover any possible criminal history, workers compensation claims, or employer sanctions.

The problem screening tries to counter

A number of annual reports, including BDO Hayward's Fraudtrack and CIFAS's (the UK's fraud prevention service) 'The Enemy Within' have showed a rising level of major discrepancies and embellishments on CVs over previous years.
Such business fraud cost UK businesses 1.4 billion in 2005.

Almost half (48%) of organizations with fewer than 100 staff experienced problems with employees.

Larger companies are more likely to outsource than their smaller counterparts - the average staff size of the companies who outsource is 3,313 compared to 2,162 for those who carry out in-house checks.

Financial services firms had the highest proportion of respondents who outsource the service, with over a quarter (26%) doing so, compared to an overall average of 16% who outsource vetting to a third party provider.

The construction and property industry showed the lowest level of outsourcing, with 89% of such firms in the sample carrying out checks in-house.[6] there for making the overall average 16%. This can increase over the years.

Employment References
Education Verification - School grades, degree and any professional qualifications obtained
Character Reference Check
Gaps in employment history
Identity and Address Verification - whether the applicant is who he or she claims to be. Generally includes verification of the candidate's present and previous addresses. Can include a money laundering, identity and terrorist check and one to verify the validity of passports (UK and international).
Whether an applicant holds a directorship
Credit History - bankruptcies
Criminal History Report

There are a variety of types of investigative searches that can be used by potential employers. Many commercial sites will offer specific searches to employers for a fee. Services like these will actually perform the checks, supply the company with adverse action letters, and ensure compliance throughout the process. It is important to be selective about which pre-employment screening agency you use. A legitimate company will be happy to explain the process to you.

Many employers choose to search the most common records such as criminal records, driving records, and education verification. Other searches such as sex offender registry, credential verification, reference checks, credit reports and Patriot Act searches are becoming increasingly common. Employers should consider the position in question when determining which types of searches to include, and should always use the same searches for every applicant being considered for one position.

They are frequently conducted to confirm information found on an employment application or résumé/curriculum vitae. They may also be conducted as a way to further differentiate potential employees and pick the one the employer feels is best suited for the position. In the United States, the Brady Bill requires criminal checks for those wishing to purchase handguns from licensed firearms dealers. Restricted firearms (like machine guns), suppressors, explosives or large quantities of precursor chemicals, and concealed weapons permits also require criminal checks. Checks are also required for those working in positions with special security concerns, such as trucking, ports of entry, and airline transportation. Other laws exist to prevent those who do not pass a criminal check from working in careers involving the elderly, disabled, or children.

Due to the sensitivity of the information contained in consumer reports and certain records, there are a variety of important laws regulating the dissemination and legal use of this information. Most notably, the Fair Credit Reporting Act (FCRA) regulates the use of consumer reports (which it defines as information collected and reported by third party agencies) as it pertains to adverse decisions, notification to the consumer, and destruction and safekeeping of records. If a consumer report is used as a factor in an adverse hiring decision, the consumer must be presented with a "Pre-adverse action disclosure," a copy of the FCRA summary of rights, and a "notification of adverse action letter." Consumers are entitled to know the source of any information used against them including a credit reporting company.

The amount of information included on a check depends to a large degree on the sensitivity of the reason for which it is conducted-e.g., somebody seeking employment at a minimum wage job would be subject to far fewer requirements than somebody applying to work for the FBI.

Criminal and incarceration records
Birth certificate, citizenship, or legal status in the country
Litigation records
Employers may want to identify potential employees who routinely file discrimination lawsuits. It has also been alleged that in the U.S., employers that do work for the government do not like to hire whistleblowers who have a history of filing qui tam suits.
Driving and vehicle records
Employers in the transportation sector seek drivers with clean driving records--i.e., those without a history of accidents or traffic tickets.
Drug tests
are used for a variety of reasons--corporate ethics, measuring potential employee performance, and keeping workers' compensation premiums down.
Education records
These are used primarily to see if the potential employee had graduated from high school (or a GED) and in fact received a college degree, graduate degree, or some other accredited university degree. There are reports of SAT scores being requested by employers as well.
Employment records
These usually range from simple verbal confirmations of past employment and timeframe to deeper, such as discussions about performance, activities and accomplishments, and relations with others.
Financial information
Credit scores, liens, civil judgments, or bankruptcy may be included in the report.
Licensing records
A government authority that has some oversight over professional conduct of its licensees will also maintain records regarding the licensee, such as personal information, education, complaints, investigations, and disciplinary actions.
Medical, Mental, and Physiological evaluation and records
Military records
Although not as common today as it was in the past fifty years, employers frequently requested the specifics of one's military discharge.
Social Security Number
(or equivalent outside the US). A fraudulent SSN may be indicative of identity theft, insufficient citizenship, or concealment of a "past life".
Polygraph test
Also known as a psychophysiological detection of deception (PDD) examination.
Other interpersonal interviews
Employers will usually wish to speak with potential employees' references to gauge employability. More intensive checks can involve interviews with anybody that knew or previously knew the applicant--such as teachers, friends, coworkers, and family members.