The Supreme Court on Friday sought the Centre’s response to four petitions challenging the constitutional validity of the Aadhaar Act and the directives making it mandatory to link bank accounts and mobile number with the unique identification number.

The bench also directed banks and telecom providers to mention the deadline to link Aadhaar numbers with bank accounts and mobile numbers in the text messages they send customers – people have till December 31 to link their bank accounts and till February 6 for their mobile numbers. The judges observed that the messages sent at present imply that customers have to link their accounts right away, the Hindustan Times reported.

In a fresh affidavit, the Centre said it may change the deadline to link the unique identification number with bank accounts to March 31, including for those who already have their Aadhaar cards.

On Thursday, the top court had agreed to hear the matter after it was mentioned before a bench headed by Justice J Chelameswar, PTI reported. Mathew Thomas from Karnataka had moved the court, saying the Aadhaar Act infringes upon an individual’s right to privacy, and also claimed that the biometric mechanism did not work.

The bench reiterated that it will hold the final hearings of a number of petitions against making Aadhaar-linking compulsory in the last week of November. On October 30, the Supreme Court had said it will form a five-judge Constitution Bench to hear the pleas.

The Centre has made it mandatory to link more than 50 schemes with Aadhaar. It was also made compulsory to file Income Tax returns, even though the Supreme Court had restricted linking Aadhaar to six schemes. Several petitions have been filed in the Supreme Court against this linking.

A bench headed by Chief Justice of India Dipak Misra listed the case after Attorney General KK Venugopal said the Centre will not extend its December 31 deadline to link Aadhaar with mobile numbers and bank accounts for citizens already enrolled in the programme. On October 25, the Centre had said it was willing to extend the deadline to March 31 only for those who have yet to get an Aadhaar card.

In a landmark ruling in August, the Supreme Court had declared privacy a fundamental right protected under Article 21 of the Constitution. This was seen as a major blow to the Centre’s push for Aadhaar.

Corrections and clarifications: An earlier version of this story erroneously suggested that the government had already extended the deadline to link bank accounts with Aadhaar to March 31.