For most parents, the most important part of hiring a new caregiver is making sure they’re offering the job to someone they can trust. That’s why so many parents seek referrals from people they know, used trusted agencies like Westside Nannies, and run background checks to vet potential candidates. But there’s one other tool that every parent should have in their arsenal — one that Westside Nannies relies on for every nanny hired — and that’s TrustLine.

TrustLine is a database of nannies, babysitters, and other in-home childcare providers who have passed a comprehensive background screening in the state of California. TrustLine screens candidates using three databases that the general public, including private investigators and private background check companies, cannot access. “This is the only background check for babysitters and nannies in the state of California that accesses the California Department of Justice and the FBI for criminal history,” Cindy Mall, a senior program manager for the California Child Care Resource & Referral Network, tells Westside Nannies. “In California, that includes arrest and conviction information by fingerprint, and it’s the only background check that accesses the Child Abuse Central Index at the California Department of Justice.”

The Child Abuse Central Index is a unique database in that it shows not only people who have been arrested for or convicted of child abuse, but also those who have been the subject of child abuse investigations that found a high likelihood of substantiated claims of abuse and neglect—even if the investigation did not result in an arrest. “That information is highly confidential,” notes Mall. “That, and fingerprint information, is not accessible to the general public.”

The other really unique thing about TrustLine is that it cross-references other databases to look for problems that wouldn’t necessarily show up on a standard background check. The system checks teacher credentialing, child care licensing, and assistant nursing certifications in the state of California, and individuals who have a revoked certification cannot be registered on TrustLine to care for a child in someone’s home. A standard background check likely won’t show licenses or certifications that have been revoked unless it’s attached to a criminal conviction, but TrustLine does in order to allow families to make informed decisions about who they hire.

Despite its popularity among agencies and day care facilities, many parents who are hiring nannies independently still don’t know about TrustLine. But the database is one of the easiest and clearest ways to be certain about the candidate you’re choosing to care for your children. And perhaps the best part is that the TrustLine database updates continually, so any new information that surfaces down the road will still be added and accessible.

Some nannies are already registered on TrustLine so parents can easily look them up. To see if a provider is already registered, all you need is their full name and their driver’s license number. If they aren’t already registered and you want to add them to the database, the first step is to have them fingerprinted and fill out an application. The TrustLine website has step-by-step instructions for how to do all of that. Once the application is complete, you then mail it to the Department of Social Services. On average, it typically costs around $130-$150 to have the application processed, but the peace of mind it brings can be priceless.

Most nannies are true professionals who go into the industry for the right reasons and love caring for children of all ages. But it’s still important to do your due diligence when hiring someone new. Trust is the most important part of any parent-caregiver relationship, and TrustLine is one of the best and easiest ways to start building a solid foundation for that.