PSA: Your Venmo transactions are public by default.
Venmo fancies itself as a social network rather than a payment service and as such makes your transactions public by default. You have to change a setting if you'd rather keep your Venmo comings and goings private, otherwise Venmo users are able see when you make or receive a payment.
Thankfully, it's easy to set your Venmo activity to private, either globally or per transaction. Let's quickly review your options.
When you're sending a payment, you can tap the button in the lower-right area just above the big, blue Pay button to choose one of three options:
Again, by default, Public is the selection.
To set your Venmo activity private, tap the hamburger icon in the top left, tap Settings and then tap Privacy. Under Default Privacy Setting, tap Private and continue to use Venmo as you have from the start -- as a payment service rather than social network.