Private mortgage servicers face some of their most demanding reporting obligations at year-end, when every non-performing note must be accurately classified, valued, and disclosed. This guide covers the core elements of NPL reporting: defining non-accrual status, recognizing collateral impairment, documenting interest and fee treatment, tracking active legal proceedings, and summarizing loss mitigation outcomes. It also addresses how to meet the distinct reporting expectations of individual investors, institutional funds, and state regulators - and how purpose-built servicing technology makes consistent, auditable documentation achievable at scale. Accurate year-end NPL reporting is not a compliance checkbox. It is the annual record that demonstrates portfolio management competence, sustains investor trust, and positions a servicer for continued business.