A DBK file is a mobile phone backup file created by Sony Ericsson PC Suite, a program used to manage Sony Ericsson mobile phones. It contains multiple Zip-compression files that store various phone information such as the names and phone numbers of contacts. DBK files are used to back up phone information in the event that the phone is lost or broken.

DBK files can be opened with various programs, such as Sony Ericsson PC Suite, FJ Software Development MyPhoneExplorer, and Amrak Software phoneMiner. The files can also be decompressed with a Zip-decompression utility, such as Microsoft File Explorer, Corel WinZip, and Apple Archive Utility. To decompress a DBK file, rename the .dbk file extension to .zip and then decompress and extract the contents with the ZIP-decompression program. The contents, which may include a .VCF contacts file named contacts.vcf can then be opened with a program that supports the file type. After extracting the contents, compress the files as a .ZIP file, then rename the .zip file extension to .dbk.