“One day, Jeff literally looked at me and said, ‘Hey, wouldn’t it be fun if we could get dressed up and go to a wedding?’” Karina told Fortune.

Her first answer was you can’t just do that: They didn’t know anyone getting married, they themselves got married and had kids relatively young, and they certainly weren’t going to crash a wedding—just yet.

So the two started chatting and wondered if there was a resource where they could get connected to couples having a wedding in their area who needed a seat-filler of sorts. Jeff looked into it and found nothing like it existed. So, the San Diego couple built it.

Not a Wedding Crasher, which launched in mid-March, lets couples share unused wedding seats with verified guests, who pay a fee set by the couple to attend the ceremony and reception. And it’s solving a pretty common problem: Jeff said an estimated 10% to 20% of invited guests RSVP no or drop out, and many venues require couples to pay for a minimum headcount whether they fill it or not.

“You may have to pay for 100 seats, and you can only get 75 people,” he said. And those empty chairs are costly: The Knot’s 2026 Real Weddings Study found the average cost per wedding guest is $292, and the average guest count is 117. Their website allows to-be newlyweds to list what Jeff called “unused capacity” and get them filled. Listings on the site have ranged from one open seat to 60.

How it works

Couples sign up as hosts and list how many seats they have open and what they want to charge. Jeff said couples have set prices from $25 to $150 a seat, with an average of about $50. Current listings include a $25 seat outside Nashville and 19 open seats at $70 each at a Las Vegas wedding next month.

The Besens review every listing and contact the couple before it goes live, to weed out fake accounts. Guests sign up for free; build a profile with a photo, a short bio and links to their social media; and verify their identity by scanning a government ID and their face through Stripe. They then request a seat with a short note to the couple, who approve or decline from a dashboard. Only after approval does the guest learn the venue name and address.

The company takes a 20% platform fee on each seat’s price, plus what Jeff called a “relatively nominal” service fee charged to guests on each transaction.

The platform has processed “tens of thousands of dollars” in gross seat payments, Jeff said, of which it keeps 20%.

“This is also a largely software business, so we do have pretty high margins,” he said. He added the couple is looking at other ways to expand revenue.

From a dozen seats to 20,000 sign-ups

Growth has come almost entirely from social media. The Besens make short videos about each new listing and push them to the cities where the weddings are.

The site’s first wedding came in May in Los Angeles, and the Besens went themselves.

“We are based in San Diego, so fortunately that was relatively close,” Jeff said. “As any good business owner, you should be eating your own dog food, if you will. So we had to go and try it out.”

The couple had never crashed a wedding before building the site.

“We are fairly private people, and this has totally flipped us upside down,” Jeff said. Karina added they’ve had to learn to put themselves out more publicly, since they now make videos for every new listing.

In May, they had sold about a dozen seats and had 300 guests on the platform, but five months later, Jeff said the site has placed close to 1,000 guests who have attended about 60 weddings, and has nearly 20,000 people signed up across the country. Guests have flown across the country to attend, alone, in pairs, and in groups. Some who met as fellow crashers now book weddings together.

Gifts aren’t required, though some guests bring them anyway.

Couples have their own reasons to sign up beyond filling paid-for seats. Jeff described a recent Atlanta wedding where the couple’s guest list skewed toward older relatives and they wanted people who would get on the dance floor. Many hosts ask for the same thing just to get the party started.

“You’re choosing your guests,” Jeff said.

A wedding season they missed

Before launch, the couple spent months testing the idea on strangers, including comedians outside comedy clubs and vendors at a wedding expo.

“Some people said it’s crazy, but most people said it’s a really good idea,” Jeff said.

The idea also has a personal side. Karina was 21 and Jeff was 23 when they married, and they had kids by the time she was 23.

“You know how some people get to go to weddings every weekend for a year? We didn’t really get to do that,” she said. “We had too much responsibility at home.”

Their own wedding ran into the same venue minimums their site now works around. Their preferred venue required at least 100 guests on a Saturday. With only 50 or 60 people, they married on a Sunday instead.

Karina said she didn’t expect the personal connections. One guest wrote in her profile that she had always wanted to be an adult flower girl. And it came true, thanks to the site.

“That bride that she applied to the wedding actually asked her to be her adult flower girl in the wedding,” Karina said.