Adding a Hidden Field in MarketoAdd a hidden field to a Marketo form to pass data into LeanData BookIt for Forms. Step-by-step field setup.May 7, 2026Knowledge
InformationTitleAdding a Hidden Field in MarketoURL NameAddingaHiddenFieldinMarketo6901f2ec9fea4Step-by-StepTo link LeanData's routing and scheduling process to the leads or contacts created through your Marketo form, you'll need to add a hidden field to your form using the steps below. This hidden field stores the BookIt Log ID that will later be passed to the Salesforce record via your marketing automation platform. If you already have a custom method to accomplish this, feel free to skip this guide and use the approach that best fits your workflow. Step 1: Create a Custom Field on Your Salesforce Lead/Contact Object Create a new Text field on the Lead and/or Contact object in Salesforce with a minimum length of 50 characters. 🛠️ Ensure that this field is synced over to Marketo via a two-way sync. Step 2: Add The Hidden Field to Your Marketo Form In your Marketo form editor, add a new field that corresponds to the custom Salesforce field you created in Step 1. Field Type: Set this to Hidden.Form Pre-Fill: Make sure this is set to Disabled to prevent old values from populating the field. This ensures the form can accept the BookIt Log ID dynamically via JavaScript without interference from cached or pre-filled values.