Importing Contacts to iCloud

See the steps in the articles Import contacts into Contacts on Mac - Apple Support

If an app can’t import vCards into Contacts on Mac - Apple Support

Change vCard settings in Contacts on Mac - Apple Support

When you are exporting contacts from another Mac and importing in another Export or archive contacts in Contacts on Mac - Apple Support

Use this step .

Export all contacts

• In the Contacts app on your Mac, choose File > Export > Contacts Archive, choose a location, then click Save.
• The contacts are exported as an archive file (.abbu) only.

Hi Mthrof7inTX,

Thanks for posting in Apple Support Communities.

We understand that only a portion of your contacts are loading into iCloud. Do you get an error for that contacts that aren't loading.

Make sure you're adding contacts using these steps:

1. In Contacts on iCloud.com, click  in the sidebar, then choose Import vCard.

Select a vCard to import.

2. Contacts from imported vCards are added to the All Contacts group. You can add contacts to any other group by dragging them. See Create and manage groups of contacts on iCloud.com.

You can find these and additional steps Import or export a vCard in Contacts on iCloud.com.

Regards.