Before filing a portable document file (PDF) in CM/ECF, a document in a fillable format must be converted through a process known as flattening so that it can no longer be modified. This is REQUIRED before filing any documents in CM/ECF. Please see the instructions below for how to flatten a pdf:
 
A flattened PDF cannot be edited by other users and avoids potential issues with the display. As an added measure, the NextGen CM/ECF software that checks for PDF compliance will reject non-flattened PDF files that contain fillable fields.   
 
Instructions and several helpful tips are posted on the PACER website.
https://www.pacer.gov/psc/hfaq.html
 
How do I make sure my fillable PDF cannot be edited by other users? 
To prevent users from editing your form fields in a fillable PDF, you must "flatten" or lock the form before saving. 
1. Open a fillable form and add the necessary data. 
2. Click File and select Print. 
3. Select the "Adobe PDF" printer and click OK or Print. 
4. In the pop-up window, select where to save the "flattened" version of the form. 
5. Click Save and file the form in CM/ECF. 
The document should now be "flattened" and cannot be altered.