Tracking money friends owe you (IOUs)

Updated 2026-05-19 · 4-minute read

The forgotten IOU is one of the most common friction points in friendships. You lend your brother $200 for a deposit; six months later you remember vaguely; you don't want to bring it up; and now you're both quietly resentful about a number neither of you remembers exactly.

The fix is mechanical: log it when it happens, log every repayment, get reminded when nothing's moved for a while. None of this requires bank linking, an account, or a subscription.

The pattern

Step 1: Log the IOU when it happens

Open Penno → Debts tab → Add Debt. Fields:

• Name: who. "Ahmed (brother)", "Marina from work", "Dad — deposit help".
• Total amount: what they owe in total.
• Note: why. "Wedding deposit", "split Uber to airport".
• Start date: today by default.

You don't need a due date or payment plan for casual IOUs. Skip those fields — they're for structured debt (credit cards, formal loans).

Step 2: Log each repayment

When they pay you back — partial or full — open the debt and tap "Add Payment". Each payment gets:

• Amount: how much they just gave you.
• Date: today, usually.
• Note: how they paid. "Venmo", "$20 cash at dinner", "transferred to checking".

The note is the part that makes this workflow valuable. Six months later when you're looking back, "Venmo $50 on Oct 12" is clear; "$50 payment on Oct 12" with no note is ambiguous.

Step 3: Let the stale-debt reminder do the awkward part

If an IOU goes untouched for a configurable period (default ~30 days), Penno sends you a quiet notification: "Ahmed (brother) hasn't moved in a while". You choose whether to bring it up. The app doesn't text your brother — it just reminds you.

This is the single feature that solves the "forgot about the loan" problem. Set-and-forget would be nicer, but in practice the gentle nudge is what actually closes the loop.

Real example

Imagine you lent your sister $300 for a car repair. Over three months she pays back:

• Sep 14: $100 in cash at family dinner
• Oct 02: $50 via Venmo
• Oct 28: $100 in cash
• Nov 12: $50 via Venmo (full settlement)

In Penno you see a timeline: original amount $300, four payment rows with dates and notes, balance dropping to $0. When she finishes, the debt auto-archives. The whole history is searchable and exportable.

The alternative — a mental note that "she still owes me a bit" — works for nobody.

What about Splitwise?

Splitwise is great for ongoing shared expenses (a group of roommates splitting groceries, a couple managing date-night costs). Penno is better for occasional bilateral IOUs — you don't need a group, you don't need them to install an app, you don't need real-time settlement features.

Some users run both: Splitwise for active shared budgets, Penno for the casual loans that don't fit into a "group."

Privacy implications

Splitwise and similar apps store your IOU data on their servers, including the names of the people involved. If you're tracking sensitive financial relationships (loans to a family member you'd rather not have logged anywhere), a local-only app like Penno keeps the data on your device. The other party never has to know they're "in" an app at all.

Frequently asked questions

See also: Debt payoff tracking