Locksmithing requires specialized skills and knowledge, attention to detail, spatial perception, hand-eye coordination, and manual dexterity. Ideally, locksmiths will also be prompt, charge reasonable fees, and leave behind locks and keys that work flawlessly for a long time.

Fortunately, most locksmith services are up to the job. When we surveyed homeowners in seven major metropolitan areas for their feedback on locksmiths they had used, most of the companies were rated “superior” for “overall quality” by at least 85 percent of their surveyed customers. But a few received dreadful reviews.

One simple step for protecting yourself from defective locks or lousy locksmithing is to pay by credit card. The Fair Credit Billing Act and the dispute-resolution policies of credit card issuers allow consumers to refuse payment for faulty products and services.

Since many local locksmith outfits get high marks from their customers for service quality, obtain prices from a few to make sure you don’t pay too much. You’ll find that prices vary widely from company to company for the same work.

Our undercover shoppers asked companies for price quotes on four jobs. Company-to-company price differences varied substantially. Fortunately, you don’t have to pay more to get the best service: We found that several of the highest-rated locksmith services also charge low fees.

Although our shoppers gave each company the same description for each job, there might be differences in the quality of materials and workmanship.

If you know what you want done, shop for prices by email or phone. If you’re not sure, ask locksmiths who visit your home for a written description of the work and how much they’ll charge.

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