I ran into this when I had separate vCard files from iCloud, Outlook, and an old Android backup. Manually combining them in Notepad technically works, but it’s risky. One small formatting issue and the file won’t import properly. Plus, duplicates become a headache.
What worked for me was WholeClear Merge vCard Software. It lets you add multiple VCF files or even an entire folder at once. The tool merges them into a single VCF without changing contact details or structure. It also supports different vCard versions, which matters if your files come from different sources.
You just load the files, choose the save location, and merge. Quick, clean, no drama. You can test the tool for free.