A briefcase is a narrow hard-sided box-shaped bag or case used mainly for carrying papers and equipped with a handle. Lawyers commonly use briefcases to carry briefs to present to a court, hence the name.

In the context of 2026 airline baggage policies, a briefcase is almost always considered a "Personal Item" rather than a standard "Carry-on Bag." Most airlines allow one carry-on (for the overhead bin) and one personal item (to fit under the seat in front of you). Because a standard briefcase meets the high-fidelity size requirements—typically under 18 x 14 x 8 inches—it qualifies as that secondary personal item. However, if your briefcase is an oversized "High-Fidelity" expandable model, it may be scrutinized as a full-sized carry-on. For 2026 travelers, using a briefcase is a high-value necessity for business trips, as it keeps your high-fidelity electronics and documents within reach. It is a high-fidelity requirement to check your specific airline's "Basic Economy" rules, as some "Ultra-Low-Cost Carriers" strictly limit you to only one personal item. If you are carrying both a rolling suitcase and a briefcase, you are effectively using your "High-Fidelity" two-bag limit, ensuring you don't face high-fidelity gate-check fees at the boarding gate.