You can block a contact to prevent them from contacting you. In addition to blocking a contact, you can also choose to Report abuse, this notifies us of spammers so we can stop them in the early stages of their activity.

To block a contact and report abuse:

1. Go to the Contacts or Recent tab, right-click the contact’s name and select Block This Person...
2. In the message box, tick Report abuse if you wish to alert Skype of a nuisance contact.
3. Click Block.
   
   

If you wish to unblock a contact:

1. In the main menu, select Tools > Options.
2. In the Skype Options box, select Privacy > Blocked Contacts. A list of blocked contacts is displayed.
3. Select the contact you wish to unblock and click Unblock this person.