Fill custom CRM fields in Bitrix via REST API

I have the need to fill custom fields in Bitrix24 CRM via REST API.

When it comes to working on standard fields (like TITLE, TEL, etc) it works, but if I try to valorize a custom field by putting it’s property name in the request the endpoint simply ignores it.

Here you have a snippet:

$company = CRest::call(
    'crm.company.add',
    [
        'fields' => [
              "TITLE" => "Company 1"
            , "COMPANY_TYPE" => "Customer"
            , "CURRENCY_ID" => 'EUR'
            , "REVENUE" => "123000"
            , "ADDRESS" => "st. some address"
            , "ADDRESS_CITY" => "some city"
            , "ADDRESS_POSTAL_CODE" => "12345"
            , "ADDRESS_PROVINCE" => "some province"
            , "PHONE" => [
                         ["VALUE" => "1230000000", "VALUE_TYPE" => "WORK"]
                        ,["VALUE" => "1234000000", "VALUE_TYPE" => "FAX"]
                     ]
            , "EMAIL" => [ ["VALUE" => "[e-mail]", "VALUE_TYPE" => "WORK"] ]
            , "INDUSTRY" => "MANUFACTURING"
            , "CUSTOM_FIELD" => "Hey I'm not a standard field and I'm going to be ignored"
        ]
    ]
);

Did anyone have the same need? How can I solve it?

Answer

I found the solution. Simply write the Field ID instead of the Field Name. The Field ID looks like “UF_CRM_5AERER454DD4″. By putting this as key and the value after ” => ” the property gets valorized.