For safety reasons, you will need a Bike Hub account and be logged in with that account to respond to most advertisers. If you do not have a Bike Hub account, you can register for free here.
Navigate to the advert that you want to respond to. Under the Seller's Profile you may see the following contact options:
1. Send a message (on all adverts)
2. Show phone number (optional)
3. Send email (optional)
The 'Send a message' button lets you contact the Seller via the Bike Hub messaging system. The Seller will be notified of your message through the on-site notifications and their email.
If the Seller has elected to show their email address and phone number, you can click on 'Show phone number' or 'Send email' to contact them directly through these channels.