There’s no such thing as a bad day when you’re fishing — and no such thing as extra baggage charges when you wear a fishing vest.

Travel hackers on TikTok are putting function before fashion in the latest trend, which sees savvy airline passengers using pocket-laden vests — typically worn by anglers to carry their myriad gizmos — to carry belongings they can’t fit into a carry-on.

In a clip with over 1.8 million views, TikTok user @cheapholidayexpert carefully tucks various items into the many pockets of the vest — including a portable speaker, stick of deodorant, pack of cards, and bikini. She even manages to shove a laptop into a larger pocket in the back of the vest.

“After stuffing my pants in a neck pillow and using a duty-free bag, it was only time before I reached the heady heights of leisurewear,” Cheap Holiday Expert jokes in the video’s caption.

The fishing vest hack is a variation on other air travel hacks that have made the rounds on the app. Previously touted strategies have included stuffing extra clothes into a travel neck pillow and wearing multiple layers of clothing aboard the plane, all in the name of avoiding an extra charge.

Other TikTok creators have tried this new hack and say that it helped them avoid additional checked-bag charges.

“Great travel hack for budget airlines and early check-ins,” creator Natasha Hunt-Stanley gushes in a clip, adding it’s helped her “get around those high [baggage] charges.”

In an email to The Post, Hunt-Stanley, who lives in the UK, said she’s used the trick “five times, [over] eight flights and one train journey.”

“When I wear [the vest] over a black outfit, it’s barely noticeable,” the thrifty traveler said, adding it’s worked “absolutely every time.”

In the clip, she shows herself wearing a fishing vest, smaller pockets packed with travel essentials like chargers, earphones and snacks, and larger pockets stuffed full of clothes.

The user then shows herself taking a tote bag out of the vest and stuffing the vest into it.

“So I don’t look like a crazy person,” she joked.

In another video, attorney and frequent traveler Julie Waters tests the technique with a fly-fishing vest for her upcoming Spirit Airlines flight.

In her video, Waters claims to have stowed a week’s worth of clothing into her vest. Along with her carry-on luggage, the mom successfully made it through security without having to pay for an additional item.

“No one batted an eye, but a friend did make a comment that someone could have thought you were some kind of crazy Unabomber-type person so that would be the biggest downside,” she told the Wall Street Journal. “What I really want to try is the pillowcase one, where instead of a pillow it’s full of clothes.”

For Hunt-Stanley, who frequently travels with budget airlines such as EasyJet and Ryanair, it’s a game changer.

“It’s such a winner for budget airlines and early check-ins,” Hunt-Stanley said. “Especially when there is a pool to lounge around.”

The Post has reached out to Ryanair, Spirit Airlines and EasyJet for comment.