It's highly possible that you would have lost your PAN Card and do not remember where you have kept the same. It's also possible that your wallet has been stolen or lost and the PAN card was in it.
Now there are two things that can happen: One is that you have another photocopy of the PAN Card and the other is that you have no photocopy and you do not know the PAN number.
In case you do now know the PAN number it is best to apply for a duplicate PAN Card. Please visit https://tin.tin.nsdl.com/pan/
In case you remember your number or you have a photo copy, you may not need to apply, because in most of the cases you need just a photocopy.
It is very rare that somebody will ask you to submit your original PAN card for verification. In fact, the PAN cards issued in the 1990s, were black and white and looked like photocopied PAN Cards, which were later laminated.
In any case you might not need an original PAN Card at all, though it's always a good idea to apply for one.
There are a number of places where a PAN Card is needed though they may not verify with the original PAN Card.
You may need PAN Cards At the Following Places:
1) Bank will ask you for a PAN Card when you open a new account.
2) When you purchase a property, whether buying or selling you may need to furnish it.
3) It would also be needed when you are buying a vehicle
4) When a hotel payment exceeds Rs 25,000, you may need to show your PAN card.
5) In case jewellery purchase exceeds Rs 5 lakhs, you may have to show it to the jeweller.
6) If your bank deposits exceeds Rs 50,000 you may have to furnish your PAN Card.
7) You cannot open a demat and trading account without a PAN Card.
As mentioned earlier, there maybe a need to apply for a PAN card in case you do not remember the same. However, you can still file returns and undertake important transactions with a photocopy of the PAN Card.
Of course, the best option would be to apply for a duplicate PAN card.