Please find a helpful link in this regard, below:
13th August 2018 From India, Delhi
It would be courteous to call and speak to the HR of the previous employer and requet them that you would be emailing a Confidential Verification format, which they should fill and return by email.
During the conversation it would be prudent to check if there is anything averse against the employee being considered for employment, as most HR do not mention such things in the Verification format.
15th August 2018 From India, Mumbai