I didn't pay for the goods that his friend introduced to his friend, and his friend asked his friend to write an iou. My friend also testified in court, and the iou was written by his friend.

You can still sue if you don't have an iou. However, in order to get the support of the judgment of the people's court, in addition to the debtor's own admission, the creditor must also provide corresponding evidence, otherwise it will bear the risk and responsibility of losing the case.

Evidence includes direct evidence and indirect evidence, and IOUs belong to direct evidence. In the absence of IOUs, creditors can support their claims by providing indirect evidence such as witness testimony, audio recordings, short messages, chat records and remittance vouchers.

It is suggested that when creditors collect some evidence through some means, they can confirm that you have a real and effective creditor-debtor relationship through the debtor's admission, such as negotiating with the debtor, recording or other recording methods; Urge the debtor in writing and ask the other party to sign for confirmation.

And then go to court to solve it. This kind of creditor's rights must be settled as soon as possible, which may exceed the limitation of action. As long as it's not more than two years since the last time you recover the arrears from him, if it's more than two years, it's beyond the limitation of action, and the debtor has the right of defense, and the court will not support your request.