Go to mailchimp.com and login to your account
Click the Audience icon on the left-hand side
Click Add Your Contacts
Choose between the two options
For Upload File, click Browse and select the file you want to upload then click Continue to Organize
For Copy and Paste, copy your contacts from a spreadsheet like the one below and paste it on the field and click Continue to Organize
***Important: Make sure to copy this whole portion so that it will be easier for you organize your contacts.
Select the Status and click the checkbox if you wish the information of your existing contact updated every time it is added to the sheet
Create your custom Tag and press Enter
Check if the information are in the appropriate column then click Finalize Import
Click Complete Import to finish adding your audience