Reg E / Reg Z Dispute Processing — impact tolerance ≤ regulatory deadline — ITOL

Impact tolerance: ≤ regulatory deadline — any investigation exceeding the statutory window (10 business days under Reg E, extendable to 45/90 days with provisional credit; two billing cycles/90 days under Reg Z) is a breach (illustrative default — trace the derivation, then replace with your own harm analysis)

Definition: Consumer error-resolution and billing-dispute investigation process for electronic fund transfers (Reg E) and credit-card/open-end credit billing errors (Reg Z).

Why it is designated: Reg E's error-resolution timeline and Reg Z's billing-error resolution timeline are hard, statutorily defined regulatory clocks rather than discretionary tolerance bands. Any system outage that delays intake or investigation therefore directly risks a compliance breach.