The waiver of a tax exemption under Section 4 No. 9a) VATA can be revoked as long as the tax assessment for the year in which the service was rendered is still open or can still be changed under Section 164 General Tax Code. Section 9 (3) Sentence 2 VATA in the version of the 2004 Act to Accompany the Budget does not regulate the revocation.
Source: PwC DE
