> For the complete documentation index, see [llms.txt](https://docs.payshield.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.payshield.ai/transaction-processing/transaction-details/transaction-types.md).

# Transaction Types

**PAYMENT Transactions**\
Are instant & synchronous and are typically associated with a credit card transaction such as Visa or Mastercard.

**PREAUTH/SETTLEMENT**\
Are asynchronous transactions. They are used to authorise a transaction that doesn't immediately get settled (PREAUTH). These transactions can be settled either manually or using a postback from the gateway side (SETTLEMENT). Examples are ACH, Bank deposits, wire transfers.

**AUTH/CAPTURE**\
Are the same as a PREAUTH/SETTLEMENT but updated to avoid using the phrase SETTLEMENT, which can cause confusion about the payment status.

**CREDIT Transactions**\
Are transactions in which funds are credited to a recipient's credit card. They are asynchronous transactions

**VOID Transactions**\
Are used to void a transaction. If the transaction amount has not been settled /transferred to the merchant's account, there is a chance the transaction can be voided. This typically has lower processing fees than a REFUND. Not all gateways support VOID transactions.

**REFUND Transactions**\
Once a transaction has been settled / transferred to the merchant account, the transaction can no longer be VOID, so any reversals must be done via a REFUND transaction.

Each Transaction Type has a matching set of of workflow and Integration methods. They are mapped out below.

| Transaction Type     | Synchronous / Asynchronous / Redirect | Integration Methods                |
| -------------------- | ------------------------------------- | ---------------------------------- |
| Payment              | Synchronous / Redirect                | Rest, Soap, Form Redirect / Submit |
| Preauth / Settlement | Asynchronous / Redirect               | Rest, Soap, Form Redirect / Submit |
| Auth / Capture       | Asynchronous / Redirect               | Rest, Soap, Form Redirect / Submit |
| Credit               | Asynchronous                          | Rest, Soap                         |
| Void                 | Synchronous                           | Soap                               |
| Refund               | Synchronous                           | Soap                               |


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