Appeal against assessment order permits escalation through Commissioner (Appeals), Tribunal, High Court and Supreme Court or revision. Recourse against an unsatisfactory assessment order is an appeal process ascending from the Commissioner (Appeals) to the Appellate Tribunal, High Court and Supreme Court; alternatively, a taxpayer may file a revision application to the Commissioner of Income-tax. Initiating the first appeal requires Form No. 35 and payment of a prescribed filing fee under a differentiated schedule tied to assessed income slabs, with a separate fee where the subject-matter is not covered by those slabs.