(Written for the Maid of Honor and Best Man who are currently staring at a joint Excel spreadsheet, realizing that managing a 20-person combined trip is basically a part-time job.)
The joint bachelor and bachelorette party—often called a "Sten-Do" (Stag + Hen) or a "Hag-Do" (Hen + Stag)—is rapidly gaining popularity. Instead of two separate, expensive trips, the couple decides to rent one massive house in a fun city and invite both the bridesmaids and the groomsmen for a giant, combined weekend.
Logistically, it's incredibly fun. Financially, it is a ticking time bomb.
You are taking two completely different friend groups, with different income levels, different definitions of "fun," and different relationships to the couple, and forcing them to share a budget. If the groomsmen want to spend $200 each on a private boat charter, and the bridesmaids want to spend $50 each on a low-key beach picnic, forcing a 50/50 split will instantly create a cold war in the rental house.
Here is how to manage the finances of a combined Sten-Do without alienating half the wedding party.
The Base Camp: Splitting the Housing
The only expense that should be split equally among all 20 attendees is the core infrastructure: The housing and the basic groceries.
If you rent a massive 10-bedroom estate for $4,000, that cost is divided evenly. Every attendee (excluding the bride and groom, whose shares are usually subsidized by their respective wedding parties) pays their fractional share of the roof over their heads.
The same applies to the "Base Camp Groceries"—the toilet paper, the cases of water, the basic breakfast supplies, and the generic party snacks. This is the shared foundation of the trip.
The "Split-Off" Activities
A successful Sten-Do relies on the concept of the "Split-Off." The entire group of 20 people does not need to do everything together. In fact, forcing them to will ruin the trip.
Usually, the days are split: The bride takes her crew to a spa, while the groom takes his crew to a golf course or a brewery. They reunite in the evening for a massive group dinner.
The Rule of Segregated Ledgers: You must never cross-contaminate the split-off budgets. If the bridesmaids' spa day costs $150 per person, and the groomsmen's golf outing costs $80 per person, these are completely independent expenses. Do not put them in a central pot. The groomsmen should never subsidize the spa, and the bridesmaids should never subsidize the golf.
The Shared Dinner Dilemma
When the massive group of 20 reunites for a celebratory dinner, the financial tracking becomes chaotic. This is the moment where the classic "let's just split the bill 20 ways" approach usually fails.
If half the table is drinking expensive tequila shots to celebrate the groom, and the other half is drinking tap water and eating a side salad because they are exhausted from the spa, an equal split is mathematically unfair and socially awkward.
For large group dinners, you must abandon the equal split. The only fair way to handle a 20-person table is an itemized split based on actual consumption. You pay for the steak you ate; they pay for the tequila they drank.
How to Manage a 20-Person Ledger
Trying to manage a joint trip of this size using Venmo requests and text messages is impossible. The Maid of Honor and Best Man will spend the entire weekend acting as accountants instead of enjoying the party.
The only way to survive a Sten-Do is to use a digital expense tracker capable of handling large groups and complex fractional math.
When the $4,000 Airbnb is booked, you log it in the app and split it among all 20 people. When the groomsmen go golfing, the Best Man logs the $800 tee time, but he unchecks the names of the bridesmaids, ensuring only the groomsmen are charged. When the group goes to dinner, you log the receipt and assign specific appetizers and drinks to the specific people who ordered them.
By automating the categorization, the two distinct friend groups can share a house, share the celebration, and share the app, without ever accidentally paying for someone else's vacation.