The Common Admission Test (CAT) is not just another entrance test — it is the key to the top Indian Institutes of Management (IIMs) and a couple of the nation’s highest-performing B-schools. Lakhs of students vie for it every year, making it one of the nation’s most competitive academic hurdles.Last year, CAT saw more than 3.3 lakhs registering and around 3 lakhs appearing for the test, whereas CAT 2023 saw almost the same registrations and 2.9 lakh test-takers. With increasing numbers, one question continues to plague aspirants: At what point in time do you begin attempting full-length mock tests?Read | 4 Indian B-schools make it to LinkedIn’s 2025 Top 20 MBA List globally, ISB in top 5The response is found in your preparation timeline if you are preparing for CAT 2025, a matter of months, or CAT 2026, where you have not even peered beyond a year.Why Are Mock Tests Important?CAT preparation is less about understanding formulas or knowing vocabulary; it’s more about performing under pressure conditions such as the test. The paper consists of three sections – Verbal Ability and Reading Comprehension (VARC), Data Interpretation and Logical Reasoning (DILR), and Quantitative Aptitude (QA). Time management, accuracy, and coolness in all three sections is what differentiates a 95-percentiler from a 99-percentiler.Three significant functions of full-length mock tests are:Exam Simulation: Mocks simulate the two-hour pressure situation of CAT, preparing aspirants psychologically.Performance Benchmarking: Mocks are diagnostic tests that highlight strengths and weaknesses in subjects.Story continues below this adStrategy Building: Mocks enable students to test attempt strategies, pace, and question selection.Read | IIM-Ahmedabad tightens CAT entry bar for PGP 2026-28 admissions, check new criteriaFor CAT 2025 aspirantsSince CAT 2025 is scheduled on Sunday, November 30, the moment to begin taking mocks has arrived.Frequency: Begin with one or two mocks a week in September. Gradually increase to two or three a week by October. In the last week leading up to CAT, use one or two mocks to remain sharp without sacrificing burnout.Analysis Over Quantity: Mocks without analysis are a waste of time. Aim to spend two to five hours per test to go through mistakes, time-taking questions, and patterns of accuracy.Last 60 Days Strategy: Work on simulating exam-day speed through mocks. Practice spending the right amount of time on specific RC passages, how to tackle DILR sets, and which Quant questions to quickly skip.For this year’s aspirants, mocks are not a luxury anymore; they are the absolute building blocks of exam preparation.For CAT 2026 aspirantsIf you are starting early, your timeline is different. You don’t need to jump into full-length mocks immediately, instead, follow a structured cycle of Learn → Practice → Test. Without a conceptual base, jumping into full-length mocks is exasperating.Story continues below this adFoundation Phase (Sept 2025 – Feb 2026): Conceptual Building, topic tests, and sectional practice. Try not to take full-length mocks during this time.Intermediate Phase (Mar – Jul 2026): Begin with full mocks. Take two per month for March, April, and May, and three per month in June and July.Final Lap (Aug – Nov 2026): Increase the frequency of your mock schedule. Take one per week in August, and increase to two or three per week from September until the exam.This gradual scaling ensures that by the time CAT 2026 arrives, you’ll be mentally prepared for the test environment while also having mastered the syllabus.Read |10 non-IIM MBA Colleges in India: Check Ranking & placementsCommon mistakes students makeEven with the focus on mocks, the majority of candidates make unavoidable mistakes:Beginning Too Late: Waiting until October or November to commence the initial mock test may not leave much room for any flexibility in refining strategies or rectifying faults.Ignoring Analysis: Go through 20 or more mocks and analyze them thoroughly so that it doesn’t result in making the same mistakes again and again.Obsessing Over Scores: Unadjusted scores tell only half the tale. Keep track of percentile gain, accuracy levels, and consistency.Neglecting Balance: Scoring too high in Quant but ignoring VARC, or the reverse, will drag down overall performance. Mocks point out imbalances well in advance so that course correction can be made.Story continues below this adBuilding the right approachRegardless of whether you are targeting CAT 2025 or 2026, the thought process is the same: use mocks as a learning exercise, not a scorecard. The real benefit is in what they can teach. Each analysis session must address three very important questions:Which questions wasted too much time?Which concepts led to repeated mistakes?How can the strategy be adjusted to maximise attempts without compromising precision?Through constantly asking themselves these questions, candidates can make each mock a stepping stone toward real improvement.The Balanced Preparation AttitudePractice tests are not rehearsals; they are rehearsal fields for strategy, persistence, and self-assurance. Early beginnings, precise analysis, and growing frequency as the exam day loomed near are what made consistent high achievers.Story continues below this adIf you are studying for CAT 2025, mocks must now be the priority of your preparation. If you are getting ready for CAT 2026, build a strong foundation in advance and then introduce mocks in your study schedule gradually. Lastly, when to begin taking full-length mocks is no longer a matter of calendar milestones but one of being prepared to take them as a learning experience. Start when you’re ready to take the test and learn from the test. That’s how you creep closer to the IIM dream.(The author is CXO and co-founder of Toprankers)