# Migrate to Hosted Batch version 100
source: https://developer.mastercard.com/mastercard-gateway/documentation/tutorials-and-guides/migration-guides/mig-hosted-batch-v100/index.md

## Batch {#batch}

This is the Migration guide for [Batch](https://developer.mastercard.com/mastercard-gateway/documentation/api-reference/v100/rest/api-ops/index.md#batch) from versions 4 to 100.

## Payload comparison {#payload-comparison}

This table describes the request fields from Batch versions 4 to 100.

|         Field          |                         Version 4                         |                               Version 100                               |                                                                     Breaking change                                                                     |
|------------------------|-----------------------------------------------------------|-------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------|
| Endpoint version       | /version/4/...                                            | /version/100/...                                                        | URL version updated                                                                                                                                     |
| Authentication         | Certificate or Basic authentication with a blank user ID. | Certificate or Basic authentication with a blank user ID.               | Update the authentication format to include `merchant.<ID>` in the `userid`. Use `merchant.<your gateway merchant ID>` as `userid` and an API password. |
| `merchantId`           | This is a required field.                                 | This is a required field.                                               | No change                                                                                                                                               |
| `acquirer.cardType`    | This is a required field. It is an enumeration.           | This is an optional field. It is a free-form string.                    | This field is no longer required and is now a free-form string of 3 to 50 characters.                                                                   |
| `acquirer.currency`    | This is a required field.                                 | This is an optional field.                                              | This field is changed from required to optional.                                                                                                        |
| `acquirer.id` request  | This is not present in the request.                       | This is an optional field. It is an ASCII string of 1 to 40 characters. | This is a new field. You can specify the acquirer ID directly in the request.                                                                           |
| `correlationId`        | This is an optional field.                                | This is an optional field.                                              | No change                                                                                                                                               |
| `acquirer.id` response | This is always provided.                                  | This is always provided.                                                | No change                                                                                                                                               |
| `result` response      | This is always provided.                                  | This is always provided.                                                | No change                                                                                                                                               |

## Response format changes {#response-format-changes}

No new required fields or deprecated fields are introduced.