---
title: Incremental Authorisation
slug: incremental-authorisation
docTags: 
createdAt: 2025-01-14T10:04:07.001Z
---

The incremental authorisation feature allows you to increment the value of your original pre-authorisation for scenarios where you need to charge your customer a higher total amount.

By **incrementing the pre-authorisation** value, you will be able to capture the total amount that you wish to charge your customer when you are ready.

You can be assured the total amount that will be charged to the consumer can be captured at a later stage. This is because the amount is ring-fenced in the consumer’s account.

We will describe how an original pre-authorisation can be updated to include additional amounts.

:::hint{type="warning"}
There **may be** additional considerations to take into account to ensure that incremental authorisation can work with **Apple Pay™**. We will update you with any requirements, once we know more.

For **Google Pay™**, currently there are no additional considerations for incremental authorisation flows, however this may change over the course of 2026 and we will update you accordingly. 
:::

***

### Important to Consider

:::hint{type="warning"}
Make sure you are using Judopay's API version **6.21.0 **or higher.
:::

- This feature is not available with all acquirers. 
  Check with our customer service team, or your account manager for your eligibility to use this.
- You can only increment a **preAuth **that has been set up correctly.

***

## Setting up the Incremental Authorisation

An incremental authorisation **can only be used** in the context of an existing pre- authorisation. 
The end to end flow contains the following steps:

### Step One: Initial Pre-Authorisation 

- The initial step is to process a **preAuth **request. 
- When submitting the preAuth request, to **increment a preAuth** set the `allowIncrement` flag to** true **in the request body. 
  - This ensures the acquirer is expecting the amount of the initial preAuth to 
    be **amended in the future**.
- You can set the **allowIncrement** flag in the following ways: 
  - Using our SDKs when invoking a preAuth:
    - See our SDK integration sections for more details:
      - [Web SDK](docId:40dWE6LBub7vdKza1QYDC)
      - [Judokit Android](docId\:J3HOHXtGWg6_VHJo9WtzC) 
      - [Judokit iOS](docId\:prT4F78QMrSJU1gHJAWGM)  
      - [Judokit React Native](docId\:Ur8QJJ7TjDXYHf4e5aojP) 
  - Directly via the [Judopay Transaction API](https://docs.judopay.com/api-reference): 
    - As part of the POST `/transactions/preauths` request body
  - [Web Payments](docId\:GloRwwwFKFqp34FyKCXe8) (Hosted Payments):
    - As part of the POST `/webpayments/preauths` request body

***

### Step Two: Incremental Authorisation

Here, the **amount **of the initial preAuth request can be **incremented**.

- Make a call to the Judopay Transaction API using the endpoint:
  POST `/transactions/incrementalAuth`
- This request **must **contain the:
  - `receiptId` of the initial preAuth from [Step One](docId\:ME2r8nDav-sjjkWeP2rRb).
  - Additional Incremental Amount.
    - The amount sent in the `incrementalAuth` request should contain **only the additional amount you wish to authorise **and **not **the cumulative authorised total.
      For example:
      - Initial preAuth: £9.00
      - Additional amount required: £2.60
      - `incrementalAuth` request amount: £2.60
      - Total authorised amount after increment: £11.60
- The incrementalAuth step can be repeated multiple times if required. 
  - Each new increment **must **reference the `receiptId` of the original initial preAuth.

*For the purpose of this exercise, the following example is using the request body for the POST `/transactions/incrementalAuth`endpoint:*

:::CodeblockTabs
Example Request

```json
{
  "receiptId": "1001131610340495360",
  "amount": 5.99,
  "yourPaymentMetaData": {
    "internalLocationRef": "Example",
    "internalId": 99
  },
  "yourPaymentReference": "aa648425-2230-4e4e-8a61-27f06df54542"
}
```
:::

***

### Step Three: Capture the Full Amount

- To capture the full amount to collect from your customer:
  - Make a call to the Judopay Transaction API using the endpoint:
     POST `/transactions/collections`
- The amount specified in the request should include the total amount you wish to collect.
  This can be **less than, or equal to** the total amount authorised.

***

## Voiding an Incremental Authorisation Transaction

Each incremental authorisation generates its own `receiptId`. 

If an authorisation has been incremented, any subsequent void request **must **reference the `receiptId` of the **original pre-authorisation** transaction. 

:::hint{type="warning"}
Using the `receiptId` returned following an incremental authorisation will result in an **error**.
:::

The void amount **must **be the sum of the original authorisation amount and all successful increments. 
Any attempt to process a **partial void**, the sum of any but **not all authorisations** and increments, will result in an **error**.

For example:

- Initial preAuth: £100
- `incrementalAuth` request amount: £20
- `incrementalAuth` request amount: £30
- Total authorised amount after increments: £150


To void this transaction:

1. Use the `receiptId` of the Initial preAuth.
2. Submit a void request for **£150**.