Is it necessary to fill all 100 choices? I only like about 20 colleges.

You don't have to hit exactly 100 — but 20 is risky, and here's the honest math of it. The allotment engine stops at your first reachable choice, so extra choices below cost you nothing; they activate only if everything above is full. Meanwhile cutoff volatility is real: several colleges moved 50+ marks between 2024 and 2025, so a college you rated "safe" can close above your mark. If all 20 of your picks do that, you're unallotted and heading to a later round or the supplementary round (after August 31) with fewer options. The practical middle path: keep your 20 loved colleges on top in strict preference order, then honestly ask "if not these, then where?" and extend with acceptable branch-college combinations — most students can comfortably reach 60–80. Widen your acceptable set with the free TNEAhelp College-Finder.