# Account reference

Source: https://developer.avalara.com/products/communications/integration-guides/communications-integration/sov5899503670966/

Guide: Communications

# Account reference

**Element type: Required**

**Enpoints/models used:** [LineItem](https://developer.avalara.com/api-reference/communications/v2/models/LineItem/)

Your integration must provide a method for specifying a unique reference ID for each line item in an invoice. This is specified using the `ref` field in the [LineItem](https://developer.avalara.com/api-reference/communications/v2/models/LineItem/) model and can have a maximum length of 150 bytes.

**View example**:

```
"itms": [
  {
    "ref": "Reference Code for Line Item",
    "from": {
      // Location
    },
    "to": {
      // Location
    },
    "chg": 100,
    "line": 0,
    "loc": 0,
    "min": 0,
    "sale": 1,
    "plsp": 0,
    "incl": false,
    "pror": 0,
    "proadj": 0,
    "tran": 19,
    "serv": 6,
    "dbt": false,
    "adj": false,
    "adjm": 0,
    "disc": 0,
    "opt": [
      {
        // Key Value Pair
      }
    ],
    "prop": 0,
    "bill": {
      // Location
    },
    "cust": 0,
    "lfln": false,
    "date": "2018-09-23T20:31:53.452Z",
    "qty": 1,
    "glref": "General Ledger Reference"
  }
] 
```