The best advertisement is word of mouth - your customers referring you to new potentials. Standard Zoho CRM does not provide a link between leads and the contacts that referred them. It is, however, not difficult to set this up via customisation.

In Zoho CRM, open the settings menu by clicking on the tools icon on the top right of the screen.

A list of menus opens. Look for the menu called "Customization" and click on "Modules and Fields".

Navigate to the Leads module, and click on Leads. If you see a list of options for Leads module layouts, select the one you want to change. If you have not created different layouts, there would be only one available named standard. Click to open.

 The form that opens is divided into three main parts - the top right is for saving or cancelling the modifications made. The left part has all the field types you can add. The main part of the screen is a depiction of the current layout of the leads form. For this example, we select the "Lookup" field type, by dragging it from the left part of the screen to the leads form layout. You can drag the field to anywhere on the screen where it makes sense. In the example above, I have placed the "Lookup" field just under Lead Source. Once the field is dropped into the right place, click the three dots to the right of the field.

A menu appears with the following options:

For this example - we are going to select "Edit properties". There are three important things we need to do here. First, we type the label we want to show on the form (in this case: "Referred by"econd, we need to select the module where to get the related information from. Here I have selected the Contacts module. Third, a unique list name needs to be entered. In this example, I have entered: "Referring Contact Name". Since not every lead comes in via a referral, this field is not marked as "Required". You may want to tick the box for a tooltip, to make it clear to the user of the form what the purpose of the field is.