# Exemption number

Source: https://developer.avalara.com/avatax-dm-combined-erp/sales-tax-badge/transactions/cert-exemption-number/

# Exemption number

**Element type: Conditional**

**Endpoints/models used:** [CreateTransactionModel](https://developer.avalara.com/api-reference/avatax/rest/v2/models/CreateTransactionModel/)

If your application does not support CustomerUsageType/Entity Use Code exemptions, then you must include support for entering a exemption number at the transaction level. Exemption numbers are another method used for tracking those customers who have tax exempt transactions. These numbers can be a maximum of 25 characters.

**Advice:**

-   If you specify an exemption number for a document or line item, the document/line will be considered exempt, and you may be asked to provide proof of this exemption certificate in the event that you are asked by an auditor to verify your exemptions. 
-   Use`exemptionNumber` at the document level or`exemptNo` at the line level.

```
{    "lines": [        {            "number": "1",            "quantity": 1,            "amount": 100,            "taxCode": "PS081282",            "itemCode": "Y0001",            "description": "Yarn"        }    ],    "type": "SalesInvoice",    "companyCode": "DEFAULT",    "date": "2020-07-28",    "customerCode": "ABC",    "purchaseOrderNo": "2020-07-28-001",    "exemptionNo": "COA1234",    "addresses": {        "singleLocation": {            "line1": "2000 Main Street",            "city": "Irvine",            "region": "CA",            "country": "US",            "postalCode": "92614"        }    },    "commit": true,    "currencyCode": "USD",    "description": "Yarn"}
```

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