> ## Documentation Index
> Fetch the complete documentation index at: https://docs.slm.m1amdocs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# AutoBill.fetchUpgradeHistoryByVid

This method allows you to track customers’ changes in products, billing plans, and payment methods, based on the `AutoBill`’s `VID`. If you provide the VID for any item in the `AutoBill`'s upgrade history, Subscribe will return the entire series of upgrades.

Note that the VID changes each time a customer upgrades the `AutoBill`. Use `fetchAutoBillUpgradeHistoryBy` to generate a complete list of VIDs for the `AutoBill`.

## Input

*srd*: sparse response description, a SOAP string (which must be a JSON object), in which you specify the elements you want returned.This parameter enables the calling system to constrain a `method` call to return only components you specify. This gives you greater control over returned content, and improves response time within the Vindicia platform by reducing the processing needed for the call.

Some fields are required, either practically or in the WSDL, and will be returned regardless of the *srd*. A null *srd* returns the complete response.

*vid*: the ID for any revision in the `AutoBill`'s upgrade history.

## Output

*return*: an object of type `Return` that indicates the success or failure of the call.

*upgradeHistorySteps*: an array of steps or revisions in the AutoBill’s history. The `AutoBillUpgradeHistoryStep` object contains

* `vid`: the Vindicia ID for the object,
* `startTimestamp`: the date and time the step began, and
* `endTimestamp`: the date and time the step ended. This time stamp is omitted if the step is current.

## Returns

This method returns the codes listed in [The Return Object](The_Return_Object).

## Example

```

$autobillVid = 'a458e923453e3e2737a4f2142b396b100fbc8d3a';
// This code sample shows how to fetch the chain of upgraded autobills
$autobill = new AutoBill();
// now fetch the upgrade history
$response = $autobill->fetchUpgradeHistoryByVid($autobillVid); 
if($response['returnCode'] == 200) {
   $history = $response['data']->upgradeHistorySteps;
   $first_autobill_vid = $history[0]->vid;
}
```

**Parent topic:**[AutoBill Methods](../topics/AutoBill_Methods)


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.