Having your file ready is the cheapest way to get better terms — it signals a serious borrower and keeps a rate lock from expiring in underwriting. Gather these before you apply.
The property
Current rent roll; trailing 12 months (T-12) of operating statements; the last two years of property financials; a schedule of any capital improvements; existing leases; and, for a purchase, the signed contract of sale.
The borrower / guarantor
Personal financial statement (PFS); two to three years of personal and business tax returns; a liquidity statement (recent bank/brokerage statements); a schedule of real estate owned; and government ID.
The entity
Formation documents for the borrowing entity (articles/operating agreement), EIN, certificate of good standing, and the ownership/org chart. Most commercial loans are made to an LLC, not an individual.
Third-party (ordered during the process)
Appraisal and, often, an environmental Phase I are ordered by the lender after the term sheet — you don't need them up front, but budget for them in your closing costs.