> For the complete documentation index, see [llms.txt](https://doc.sysdevmobile.com/mss-extensibility/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.sysdevmobile.com/mss-extensibility/mss-5.1/functions-kalipso-to-mss/customer/ext_customer_validatenif.md).

# EXT\_Customer\_ValidateNIF

Function to ask MSS to validate a customer fiscal number (only valid for Portugal fiscal numbers)

*Input Parameters*: 

* inNIF - Fiscal number to validate; 
* inCountry - Country of the customer;

*Output Parameters*: 

* outResultCode - Return code: 0 – Fiscal number valid / < 0 – Fiscal number invalid;