Best IOU app: tracking what friends owe you

What should an IOU app do?

An IOU app should answer one question at any moment: how much does this person owe me, or I them. Four checks separate the apps that do it well from the ones that only send a request.

• A running balance per person. Not one request per loan, but a total that moves when either of you adds something.
• Part repayments. Money comes back in pieces, and the balance should drop by the piece, not wait for a full settle.
• A reminder you do not have to write. Asking is the awkward part, and an app can word it for you.
• Little work for the other person. The fewer steps they need, the more likely the balance gets used.

Here is why the net matters. Say you cover a $240 concert ticket for a friend. They pay back $60 twice, so $120 is still owed. Later they cover an $83 grocery run that you and they split equally, so you owe them $41.50. The number to track is the net: $120 minus $41.50 leaves $78.50 owed to you. An app that holds two separate requests, $120 from them and $41.50 from you, makes you both pay when one $78.50 payment would do.

If you only need a written record of one loan, an IOU note template does the job on paper. The rest of this page is about apps that keep the balance for you, and what an IOU is covers the term itself.

Which apps compare on those checks?

EvenOut, Splitwise and Splitser all keep a balance per person, and they differ on what the free plan allows, what reminders look like and who has to sign up, as of October 2026.

App	Free plan	Reminders	Does the other person need an account?
EvenOut	No daily expense limit, no ads	A friendly email with the amount and a link, or a shared message; once a day per person	A friend balance needs them on EvenOut; a guest in a group does not
Splitwise	Up to 4 expenses a day	A “Remind” option with no Pro label	Not at first; a friend invited by email or phone can be added to expenses before accepting
Splitser	Almost entirely free; €0.35 per in-app payment	A settlement email asks for payment	No; you can add a participant by name

How does EvenOut handle an IOU?

EvenOut keeps a balance with each friend and needs no group. To record the $240 ticket, add an expense with your friend, set it to paid by you, choose Exact amounts and give the whole $240 to your friend. The Activity tab labels it “you lent”, and once the repayments and the groceries are in, the page for your friend Dan reads “Dan owes you $78.50”.

When money comes back, Settle up on the friend’s page records a partial payment as well as a full one. A part payment leaves the rest owed, so the $60 repayments show $180, then $120. If the balance comes from more than one place, say a trip group and the two of you directly, a Where it comes from section lists each source.

Remind sends a friendly email with the amount and a link, or lets you share a message yourself. It goes out at most once a day per person, and it stops if the other person turned off Reminders in their notification settings. It is not a push notification.

A friend balance needs the friend to be on EvenOut. They join with your invite link or by scanning your code, and the link lasts 30 days. If they will not install it, add them as a guest in a group instead, with their name only. A guest cannot receive reminder emails, so share a message. EvenOut records payments and does not move money, so the repayment itself happens in cash or your bank, and you record it afterwards. Adding and editing work without a connection and sync later.

How does Splitwise handle an IOU?

Splitwise tracks debts between friends as well as groups, and its Settle up records a payment made outside the app, such as cash or a bank transfer. A friend invited by email or phone can be added to your expenses before they accept the invite, and an expense with no group is visible only to the people in it.

Its balance reminder to a friend carries no Pro label. Its free plan allows up to 4 expenses a day, as of October 2026, while EvenOut’s has no daily expense limit. In the US, Splitwise can also send money through Splitwise Pay, Venmo or PayPal. For the full comparison, see EvenOut vs Splitwise.

How does Splitser handle an IOU?

Splitser has a Transfer transaction for money given outside the app, with an advance for a trip, a personal loan and a part payment of a balance as its listed uses. The payer’s balance goes up and the receiver’s goes down. You can add the other person to a list by name with no account, log everything against them, and they link to it when they join.

Everything lives in a list, so a two-person IOU is a list of two. Splitser charges €0.35 per payment made through the app, and its Offset all balances button settles the whole list at once and cannot be reversed.

Which apps work if the other person will not sign up?

In EvenOut, add the person as a guest in a group, by name, and track their share from the start. Splid, KittySplit and Spliit need no account on either side.

• Splid says no sign-up is required. A group you do not share stays on your device only, and a shared group uses an access code, with its names, titles and amounts provided to Splid so others can view and edit it.
• KittySplit needs no account to create or use a Kitty. A free Kitty holds up to 9 people, and you share it by link.
• Spliit needs no account either. Its privacy policy says anyone who has the link can read the group and change it, and its author lists no notifications and no friends feature as trade-offs.

An IOU is often private, so the link or code deserves the same care as the amount.

Are Venmo, Cash App, PayPal and Zelle IOU apps?

They ask for money in set amounts, one request at a time, rather than keeping a running balance. A Venmo request is a charge for a set amount that must be accepted before money moves, and unpaid ones sit under a Pending list where you can remind the person or delete the request. A Cash App request goes to a name, $cashtag, phone or email, and a reusable payment link can ask several people. PayPal sends a money request to anyone with an email address and lets you send a reminder. A Zelle request can only go to a person already enrolled in Zelle.

Venmo’s Groups tool does track shared expenses for up to 30 people, which is a different job from one loan. Use a payment app to collect, and an IOU app to remember. How to remind a friend to pay you back has wording for the message, and how to keep track of who owes you money covers the method behind a running balance.

How do you choose?

For most people, EvenOut is the pick: a balance per friend, part payments, a reminder you do not have to write, no daily expense limit on the free plan and no ads. Start from what the other person will actually do.

• They will install an app and you want one balance that nets both directions. EvenOut. Its free plan has no daily expense limit and no ads, and Splitwise’s allows up to 4 expenses a day.
• They will not install anything. You can track them as an EvenOut guest. Splid and KittySplit need no account on either side, if sharing a link or code is acceptable.
• It is one loan paid back in pieces. EvenOut’s part payments make the remaining amount explicit.
• You mainly need the money to move. A payment app, then log it in an IOU app so the balance stays right.

The best expense splitting apps covers the same apps for groups instead of one friend, and I owe you apps compares what a friend has to do to see the same tab.