Time limit for TDS certificate issuance: annual Form 16 and quarterly Form 16A must be issued via TRACES and authenticated. Time limits govern issuance of TDS certificates: Form 16 for salary deductions is issued annually by the prescribed deadline following the financial year, and Form 16A for non-salary TDS is issued quarterly within a short statutory period after the due date for furnishing the corresponding TDS return. All certificates must be generated through the TRACES portal, downloaded by the deductor, verified for accuracy and authenticated by digital or manual signature prior to issuance.