---
title: addSplit
slug: campaign/docs/addsplit
docTags: 
createdAt: 2026-07-02T19:01:46.338Z
---

The mailing to be converted must be of the type regular.

**Type**: void

**Parameters**

| Name      | Type   | Value                                                           |
| --------- | ------ | --------------------------------------------------------------- |
| sessionId | String | ID of the session                                               |
| masterId  | long   | ID of the master mailing to which the split mailing is assigned |
| childId   | long   | ID of the mailing assigned to the master mailing                |

**Return values**

- **Code structure**

```javascript
void addSplit(String sessionId, long masterId, long childId)
```