It’s ideal for contest holders to communicate concerns, questions and further instructions to their contest winner. This can be accomplished through private messaging, which is a contest feature to get you the best possible entry.
On the contest page, find the entry whose designer you wish to talk to and click their username on it. You will be redirected to the designer's entry page.
On the lower part of the page is the Private Message Board. You can write your message on the text box. Don't worry. Only you and contest winner will be able to see your conversation. They will be notified when a message is sent to them.
If you wish to contact the designer immediately, you can start a chat with them instead. To start a chat conversation, click on their entry on your contest page and click Chat.
Note: Do not ask for nor provide private contact information as it is against Freelancer.com's Terms and Conditions.