Defence personnel in India file income tax returns under conditions that differ from those of ordinary salaried taxpayers: special-area allowances are exempt only up to fixed monetary ceilings, remote postings delay document collection, and pension and gratuity receipts attract separate exemptions. This paper reports a descriptive operational case study of return filing for defence personnel at udChalo, a private technology platform serving the armed forces community, during the filing season for Assessment Year 2026–27. Drawing on twelve weeks of participant observation in which the author filed 128 returns (about 68% ITR-1 and 32% ITR-2), the study documents the end-to-end filing workflow and compares tax liability under the old and new tax regimes for five anonymised client profiles reconstructed from the cases handled. All liabilities were recomputed under a single procedure that applies the Section 87A rebate and the special-rate treatment of long-term capital gains. The new regime produced the lower liability in all five profiles, by margins between ₹29,120 and ₹1,46,037. Allowance exemptions of between ₹3,600 and ₹84,000 a year, together with Chapter VI-A deductions, were too small to offset the lower slab rates, the higher standard deduction and the new-regime rebate. Mismatches between Form 16 and the Annual Information Statement, late documents from remote postings and the seasonality of demand emerged as the main operational bottlenecks. The paper recommends dual-regime computation as a standard step for every client, complexity-based case routing, guided digital document collection and a year-round outreach calendar.

Keywords: income tax return, defence personnel, old and new tax regime, Section 10(14) allowances, e-filing, tax advisory, India