But the court rebuked banks and mobile phone operators saying they were creating panic with their messages warning customers about deactivating their accounts if they don't link them to Aadhaar.
When the government denied that such messages were being sent, one of the judges, Justice AK Sikri commented: "Initially I didn't want to say because the press is here, but I am also receiving such messages."
The court asked the centre to direct phone companies to include in their text messages the deadlines for linking their mobile numbers and bank accounts with Aadhaar. "We make it clear that in the messages sent by banks and telecom service providers, the date of December 31 and February 6 shall also be indicated as the last date of linking Aadhaar with bank accounts and mobile numbers," the bench said.
Petitioners have been urged to ask the constitution bench to suspend the government order if no decision is taken before the December 31 deadline.
Yesterday, the Centre told the Supreme Court that the deadline for linking mobile phone numbers with Aadhaar had been extended to February 6. Also, for new bank accounts, showing proof of Aadhaar is mandatory, it said.
Five top Supreme Court judges led by Chief Justice Dipak Misra will hear petitions challenging the validity of Aadhaar - which collects biometric details of an individual - on the ground that it violated citizens' right to privacy.
Earlier this week, while hearing a separate petition challenging the mandatory linking of mobile phones with Aadhaar, the Supreme Court had sought the government's response in four weeks.
The centre says that the 12-digit unique ID or Aadhaar assigned to citizens is a must for government services, filing returns, financial transactions and mobile phones services.
Over a billion Indians have already registered for Aadhaar cards, which ascribe unique ID numbers, and record fingerprints and iris scans of each person.