# IOU

The `IOU` vertical issues and manages trust line-based issued currencies. Each operation acts as the IOU's **issuer** — the account resolved from `from` (default: the primary signer's account) signs, and its address is the currency issuer. Callers name their own counterparty (`holder` / `to`) per call.

| Method | Description |
|  --- | --- |
| [issue](/docs/simplexrpl/references/verticals/iou/issue) | Bootstrap a new trust line-based IOU, optionally distributing an opening amount. |
| [transfer](/docs/simplexrpl/references/verticals/iou/transfer) | Send IOU value to a destination account. |
| [authorize](/docs/simplexrpl/references/verticals/iou/authorize) | Authorize a holder to hold this IOU. |
| [lock](/docs/simplexrpl/references/verticals/iou/lock) | Freeze a holder's trust line (individual + deep freeze). |
| [unlock](/docs/simplexrpl/references/verticals/iou/unlock) | Restore a frozen holder's trust line. |
| [clawback](/docs/simplexrpl/references/verticals/iou/clawback) | Reclaim a holder's balance back to the issuer. |
| [buyOffer](/docs/simplexrpl/references/verticals/iou/buyoffer) | Place a DEX order to acquire this IOU. |
| [sellOffer](/docs/simplexrpl/references/verticals/iou/selloffer) | Place a DEX order to sell this IOU. |
| [cancelOffer](/docs/simplexrpl/references/verticals/iou/canceloffer) | Cancel a standing offer. |
| [retrieve](/docs/simplexrpl/references/verticals/iou/retrieve) | Read a single IOU trust line. |
| [list](/docs/simplexrpl/references/verticals/iou/list) | List an account's IOU trust lines. |
| [listOffers](/docs/simplexrpl/references/verticals/iou/listoffers) | List all open offers in the market for an IOU. |