To convert multiple CSV files into one VCF file quickly, you need a tool that supports batch processing. I recommend WholeClear CSV to VCF Converter because it allows you to add multiple CSV files at once and export them into a single combined vCard file. This saves a lot of time compared to converting one file manually. It also keeps all contact fields like phone, email, and address properly structured. I tested it with a large contact database, and the output worked perfectly on mobile devices and Outlook.