You will not formally apply for certification until you have completed and submitted the documents listed on the PAC in FAA Order 8900.1, Figure 2-3-1A of Volume 2, Chapter 3, Section 1. Therefore, you should invest the time and resources in developing the PAC items before you begin your formal application.
At least 45 days prior to the date you wish to schedule your formal application meeting, submit the Formal Application Letter to the Certificate Holding District Office (CHDO) and include at a minimum:

• An updated Pre-application Statement of Intent (PASI) FAA Form 8400-6 only if you have made changes to the original PASI)
• Your completed proposed Schedule of Events. Indicate whether it is the original or an updated version.
• Your completed Required Management Personnel Qualification Summary Forms and Quality Audit Forms.
• Your completed list of Proposed Operations Specifications.
• At least 15 days prior to the date you wish to schedule your formal application meeting, you must submit all additional PAC items to the CHDO as listed below:
• Lease or Proof of Ownership and Facility Lease Agreements or Proof of Ownership
• Evidence of Economic Authority Request and Corporate Documents
• Deviation or Exemption Requests
• Company Manuals and Programs
• EDA Self Audit
• Compliance Statement
• Initial Cadre Check Airman Training Plan
• Outsourcing Contractual Agreement
• Current Aircraft Equipment List
• Aircraft Information Form
• Aircraft Interior Configuration Document (commonly referred to as LOPA)
• Status of Drug and Alcohol Program
• Status of Security Program
• Status of Hazardous Materials Program
• Status of Environmental Assessment