Sun Country Personal Item Size 2026: Free Bag & Fees

Every Sun Country reservation includes one free underseat item per traveler — the airline's official wording says a purse, backpack, duffel bag, "or other item if it fits under the seat in front of you," with a published maximum of 17 × 13 × 9 in (43 × 33 × 23 cm). Sun Country sells à-la-carte extras instead of fare bundles, so there is no fare without the free bag. That part is settled.

Everything else is a purchase. The carry-on — Sun Country's name for it is the "Overhead" bag — costs roughly $25–40 at booking and climbs to $65 at the gate. Checked bags start around $30–45 each way. All of it is per person, per direction, non-refundable, and priced by route and by how long you waited.

This page has the whole picture: exact dimensions, the fee ladder, the sizer boxes, the Allegiant merger, and a dated change log at the bottom — every figure verified July 2026.

Sun Country's free personal item — the site itself only ever says "underseat item" — measures a maximum of 17 × 13 × 9 in (43 × 33 × 23 cm) in 2026, and it comes with every single reservation at no charge. The one rule attached to it is refreshingly literal: it must fit under the seat in front of you.

Here's the detail most fee-anxious travelers miss: Sun Country publishes no weight limit for the underseat item. The 35 lb cap you may have read about applies only to the paid Overhead bag. If you can lift your personal item and it slides under the seat, it flies — dense packing is entirely legal.

For scale: our compression backpack measures 15.7 × 11.8 × 7.9 in (40 × 30 × 20 cm) — inside Sun Country's limit on every axis, with 1.1–1.3 in (about 3 cm) to spare per side. Not a squeeze. A category error in your favor.

Sun Country's paradox: it sells America's roomiest carry-on — the Overhead bag runs 24 × 16 × 11 in (61 × 40.6 × 28 cm) including handles and wheels, bigger than the 22 × 14 × 9 in the majors standardize on — but opening the overhead bin at all is a paid feature. The official page says it plainly: overhead bins are only for travelers who selected the overhead bag option.

The price depends entirely on when you commit. About $25–40 at booking, a flat $50 if added afterward online, $55 at the airport counter, and $65 at the gate — $55 plus a $10 Gate Handling Fee, stacked on the already-highest price. Same bag, roughly 2.6× the money. Call it the procrastination tax.

Our honest take: for a long weekend south, the free underseat item plus real compression usually beats paying at all. If your trip genuinely needs 24 × 16 × 11, buy it at booking — the gate is the single worst store on the property.

Yes and no, and the distinction is worth real money. On May 13, 2026 Allegiant Travel Company closed its $1.5B acquisition of Sun Country — a deal signed January 11, 2026 and cleared by the DOT that April. But the brands, loyalty programs and baggage policies stay separate for the next 18–24 months, so as of July 2026 a Sun Country ticket still follows Sun Country's rules.

Which produces genuine comedy: one company currently runs two different free-bag shapes. Sun Country grants 17 × 13 × 9 in (43 × 33 × 23 cm); Allegiant grants 18 × 14 × 8 in (45 × 35 × 20 cm) — an inch longer, an inch wider, an inch shallower. Book the same beach trip on the other website and your free bag quietly changes shape, and nobody at either company will mention it.

The rule that matters: your allowance follows the airline that sold the ticket, not the parent company's org chart. We track the eventual policy merge in the change log below — expected around 2027–28, not before.

Stricter than the average US carrier, for a structural reason: overhead-bin access is itself a product Sun Country sells, so gate agents actively watch who puts what where. Metal sizer boxes stand at both the ticket counter and the gate — the official page explicitly ties the Overhead bag to "the sizer box located at the ticket counter or at the gate" — and a bulky personal item that is clearly a carry-on in spirit gets sized. Fail, and the at-gate price is charged before boarding.

There's no per-bag staff bonus here, unlike Frontier's infamous commission. The incentive is built into the fee ladder itself: the airline earns roughly 2.6× more when you pay at the gate than at booking. Even a pre-paid Overhead bag that flunks the gate sizer gets checked, with possible extra charges — pre-paying doesn't exempt anyone from the box.

The only plan that works at every gate is arithmetic: a bag measuring inside 17 × 13 × 9 in passes every sizer, every shift, every mood. That's the bag we build — not a bet on a distracted agent.

No. Sun Country publishes no weight limit for the free underseat item — the 35 lb (15.9 kg) cap applies only to the paid Overhead bag. The free allowance is measured in inches, full stop.

Read that as an engineering brief: density is free. A week of compressed clothes weighs the same as a week of fluffy clothes; only one of them fits in 17 × 13 × 9 in. Fold flat, compress hard, and the size limit — the only limit that exists — stops being a constraint. Physics doesn't bill by the pound here, and neither does Sun Country.

That's exactly what our compression system is for: two hardshell halves press a week of folded clothes flat, metal buckles lock the shape, and there's no pump, no battery, nothing to charge at the hotel with the one working outlet. A padded sleeve takes a 14–15 in laptop, so the same bag covers the work trip and the beach one.

Checked bags (max 62 linear in, 50 lb) follow the same wait-and-pay-more curve: the first bag runs about $30–45 at booking, $50 after booking, $55 at the airport; the second and third are $45, then $60, then $65. The $10 Gate Handling Fee stacks on top of airport prices for any bag bought at the gate, and a fourth bag means calling Reservations, which is its own punishment.

Since September 3, 2025 the overweight staircase got steeper. The old flat +$60 for 61–99 lb became four tiers: +$50 at 61–70 lb, +$75 at 71–80 lb, +$100 at 81–90 lb, +$125 at 91–99 lb — and 51–60 lb rose to +$25. At 100 lb Sun Country simply refuses the bag, and anything 70 lb or more is refused to or from Canada, Jamaica and Puerto Rico.

Two genuine bright spots: active US military get a free Overhead bag plus two free checked bags up to 100 lb each, and Sun Country Visa Signature cardholders get 50% off the first bag pre-purchased online. Everyone else's cheapest bag remains the free one under the seat.

The dated record, so every figure above traces to a moment. April 2018 — Apollo Global Management buys Sun Country and an ex-Allegiant executive, Jude Bricker, completes the low-cost conversion: carry-on fees arrive at about $30, and the Star Tribune's headline reads, literally, "carry-ons will cost the most." Until then this was Minneapolis's cozy charter airline with free carry-ons.

April 30, 2024 — post-booking and airport checked fees rise to $50/$55 for the first bag and $60/$65 for the second; at-booking rates hold. September 3, 2025 — the overweight ladder is restructured up to +$125. January 11, 2026 — Allegiant signs the $1.5B merger; DOT approval April 15, 2026; closed May 13, 2026, with brands and bag policies separate for 18–24 months.

July 2026 — every figure re-verified against Sun Country's official bags page, the primary source for the dimensions and fees above. When a rule moves, this log gains a line the same week.