Use pending leads as a "pre-lead" status and open them when you are ready to start working on them. 

Typically, leads are in one of four statuses: open, won, lost, or canceled. It's also possible to place a lead into a pending status.

Pending leads are used specifically for the workflow of importing huge batches of leads, then opening them and assigning them to your team members at a pace that makes sense. Use the bulk edit tool to convert pending leads into open leads.

Pending leads are not assigned to a user, and are not considered part of your pipeline. They are not included in your reports until you open them. 

FAQ

Can I use the pending lead status to place leads on hold? 

We recommend cancelling leads if they're too cold, not ready to buy, or it isn't the right time. You can use automated follow through tasks to remind yourself to reach out again in the future, or manually create a task to follow back up when the lead is ready.