Step 1: Go to Listings in your dashboard
Step 2: Select the Listing you wish to mark as under offer by clicking on it
Step 3: Select Mark as under offer
Step 4: Confirm by selecting Mark as under offer
Once your listing has been marked as under offer all prospective tenants that have applied or enquired and haven't been moved to your archive will be notified of the status change for your listing.
While your listing is under offer myRent will stop sending notifications by email of new enquiries and applications but you will still see these in your listing inbox. This allows you to focus on signing up the selected tenant.
Once the tenant has been signed up and the tenancy secured with a rent in advance or bond payment the next step would be to remove your listing which will mark it as rented. You can do this by following the steps here
In the event that your tenants you selected fall through you can use the steps above to select Mark as available. This will notify all prospective tenants that had enquired or applied that hadn't withdrawn their enquiry/application that your property is available again.