Question juridique clé
Whether the emission tax claim had become time-barred before the set-off against the withholding tax refund.
Solution extraite
No. The tax claim was already due in 1996, the assessment decision had only declaratory effect, and set-off was therefore still possible.
Motifs extraits
The tax debt arose at the time of the contribution and became due 30 days later. A formal assessment does not create the claim; it merely declares it. Since set-off was already available before any limitation period expired, the claim was extinguished by set-off and could no longer later become time-barred.