Field help: (2021) Line 11 ... therein substitute assessment basis This text refers to the Online Steuererklärung 2021. You can find the version for the Steuererklärung 2025 at: (2025): Line 11 ... therein substitute assessment basis Enter here the substitute assessment basis within the meaning of sect. 43 a para. 2 Income Tax Act (EStG) according to line 11 of your tax statement.