Limitation on assessment

(1) The assessment of the levy amount is no longer permitted once the assessment period has expired (limitation on assessment). The assessment period is four years; it begins on expiry of the levy year.
(2) The assessment period does not expire for as long as the assessment cannot be made, on account of force majeure, within the last six months of the period.
(3) Where the assessment is contested, the assessment period does not expire until six months after the time the assessment became unchallengeable; this also applies where the remedy is lodged only after expiry of the assessment period. The expiry of the assessment period is suspended in respect of the entire claim. The first sentence applies accordingly to applications, made before expiry of the assessment period, for the setting-aside or amendment of the assessment.