For consultancy income that is irregular, it's preferable to file ITR-3 (Income Tax Return-3) for the following reasons: 1. _Business income_: ITR-3 is meant for individuals and Hindu Undivided Families (HUFs) with business income, which includes consultancy income. 2. _Irregular income_: ITR-3 accommodates irregular income, such as freelance or consulting work, which may not have a fixed schedule or regular payments. 3. _Expenses and deductions_: ITR-3 allows you to claim expenses and deductions related to your consultancy work, which can help reduce your tax liability. 4. _Audit and scrutiny_: ITR-3 is more likely to be selected for audit and scrutiny, which can provide an opportunity to explain and justify your income and expenses. While ITR-1 (Sahaj) is a simpler form, it's meant for individuals with income from salary, house property, and other sources, but not business income. ITR-4 (Sugam) is for presumptive taxation, which might not be suitable for irregular consultancy income. Consult a tax professional or chartered accountant to ensure you're filing the correct ITR form and taking advantage of applicable deductions and expenses.