Volumi vs Venmo: you'll probably want both
Quick honest answer up front: Venmo and Volumi aren't really competitors. Venmo moves money from one person to another. Volumi figures out who should be paying who in the first place. On a group trip you'll use both, so we actually have a lot of synergy together!
What Venmo is great at.
Paying a friend back in seconds when you're both in the US and both on Venmo. It's social, it's instant, and it's the default for a reason. For a one-to-one "you got lunch, I'll get you next time," nothing's smoother.
Where it leaves a group stuck.
Venmo has no idea that six of you spent ten days balancing budgets across two currencies, that Dave fronted the Airbnb while you covered most of the dinners. It can send $40 to one person and track a request for $60 to another, yes. But it can't tell you that, once everything nets out, Dave actually owes you $22 and Sara owes Dave $60. That accounting is the missing piece, and it's the whole thing Volumi brings together to make the money transfers smart.
How they fit together.
Use Volumi to log the trip and work out who owes who in the fewest transfers. Register your preferred payment method in your Volumi profile -- Venmo, PayPal, Wise, or your bank app -- then tap on the person you owe, copy their payment method, and go send them the money that Volumi says they're owed. Volumi then marks it settled when its all done and recorded. Done this way, you get the clean split and the payment rail you already trust, with each doing the part it's good at.
A note on currencies.
If the trip crossed a border, this matters more. Venmo is US-to-US. For an actual cross-currency transfer, Wise usually gives you the fairest rate (more on that in our Venmo vs PayPal vs Wise guide). Volumi handles the multi-currency accounting so the amount you send is already right.