Last updated: August 22, 2026
1.What Cosum is, and what it is not
Cosum is a ledger. It records what a group spent and calculates who owes whom.
Cosum does not move money. It is not a bank, a payment service, an e-money institution or a lender, and it does not hold funds. Every transfer you agree on happens outside the app, between you and the other person. Balances shown in the app are a calculation from what you entered, not a legally binding debt, and nothing in the app is financial advice.
2.Your account
You need an account to create or own a ledger. You must give a valid email address and keep your password to yourself. You are responsible for what happens under your account.
You must be at least 13 years old, or older where local law requires it.
3.People you add
Participants are names you type. Adding someone as a name means you are entering data about another person; you confirm you may do so, and you are responsible for the content of what you enter.
A participant who later joins can claim their name and take over their own entries. Entries recorded before that stay in place.
4.The numbers are yours
Cosum calculates from what you enter. It cannot know whether an amount is right, whether a split is fair, or whether a transfer actually happened. Check the figures before you settle up. Disputes between members of a ledger are between them.
5.Free and premium
The free tier is limited in the number of active ledgers, participants per ledger and entries per day, and shows a single banner advert on the summary screen. The current limits are shown in the app.
Premium removes the advert and raises the limits.
6.Subscriptions
Where premium is offered, it is sold as an auto-renewing subscription through the App Store and Google Play. Payment is taken by Apple or Google, and renewal happens automatically unless you cancel at least 24 hours before the period ends. The price and period shown at purchase are the ones that apply.
Manage or cancel in your App Store or Google Play account settings — cancelling from inside Cosum is not possible, because we are not the merchant. Refunds are handled under the store’s policy, not ours.
If you are a consumer in the EU or the UK you have a statutory right to withdraw from a distance purchase within 14 days. Because Apple and Google are the sellers of record, you exercise that right and request the refund through the store you bought from.
7.Acceptable use
- Do not use Cosum for anything unlawful, or to record activity that is itself unlawful
- Do not attempt to access another person’s ledger or account
- Do not probe, overload or interfere with the service, or automate access to it at scale
- Do not upload content that is abusive, harassing, or violates someone else’s rights
8.Availability
Cosum is provided as it is. We aim to keep it working, but we do not promise uninterrupted or error-free service, and features can change or be withdrawn. Offline mode shows the last synced data and is read-only.
9.Ending the agreement
You can delete your account at any time from Profile → Account details, or by writing to us. We may suspend or close an account that breaks these terms or puts the service or other users at risk.
When you delete your account, ledgers you own with other active members are transferred to another member so their records survive; ledgers with no one else are deleted.
10.Liability
To the extent the law allows, we are not liable for indirect or consequential loss or for lost profit. Nothing here limits liability that cannot be limited by law, including liability for death, personal injury, fraud, or our own gross negligence, and nothing here affects your statutory rights as a consumer.
11.Governing law
These terms are governed by the laws of the Republic of Türkiye. If you use Cosum as a consumer, this does not remove the protections of the mandatory law of the country where you live.
12.Changes to these terms
We may update these terms. When a change is material the app asks you to accept the new version, and the date at the top of this page changes. Continuing to use Cosum after that means you accept it.
13.Contact
Questions about these terms: support@cosum.app. Cosum is operated by Oğuzhan Ozgökce, based at İnönü Mahallesi, Bağcılar, İstanbul, Türkiye.