> ## Documentation Index
> Fetch the complete documentation index at: https://docs.equalsmoney.com/llms.txt
> Use this file to discover all available pages before exploring further.

# About card simulations

> Learn about the different type of card transactions that can be simulated in sandbox.

## Authorisations

**Authorisation** is the process of verifying the validity of a card and placing a temporary hold on the funds required to complete the transaction.

**Authorisation advice** is the process of decreasing a transaction amount after authorisation.

**Authorisation clearing** is the process of transferring the funds from the issuing bank to the acquiring bank and recording the details of the transaction with all the relevant parties.

**Authorisation reversal** is the process of releasing the hold that was placed on account funds by an authorisation and returning them to the account.

## ATM withdrawal authorisations

**ATM withdrawal authorisation** is the process of verifying the validity of a card and placing a temporary hold on the funds required to complete the transaction. In the EU, this includes authorisation for withdrawing cash at an ATM. In the US, this event indicates that the cardholder got cash from a bank teller rather than an ATM.

**ATM withdrawal authorisation clearing** is the process of completing an authorisation for withdrawing cash at an ATM.