If you lose or forget your PUK code, or enter an incorrect code three times (locking your code, something you can't unblock yourself) you'll have two options:
If you're in Estonia or able to travel quickly, you can visit the service offices of the Citizenship and Migration Bureau of the Police and Border Guard Board, or a bank, where you can get a new code envelope for your card.
If you're not in Estonia or unable to travel in the near future, you'll need to pre-order a new e-Residency card and pick it up from the nearest pickup location at one of the 38 Estonian embassies and consulates around the world, or travel to Estonia to collect it at your earliest convenience.
In order to request a new ID card you’ll need to send an email to firstname.lastname@example.org (Customer support of Estonian Police and Border Guard Board) with the following information:
Short description of the situation (e.g. saying that your current ID card cannot be used, PUK code is blocked, you need a new card as soon as possible)
Your full name
Your ID code
Number of the ID card
Name of the Embassy or pickup point (http://vm.ee/en/estonian-embassy-web-pages) where you want the card to be delivered
Ordering a new ID card will be subject to a €100 state fee and will probably take around 30 days to be delivered (sometimes faster, depending on the location).
To minimize the risk of losing your PUK code, you can set it to something more memorable. You can change your existing PUK code by following these simple steps:
Open the ID-card utility program and then 'PUK code'
Choose 'Change PUK'
Enter the existing code once and the new code twice
If the code has been changed successfully, the relevant message will appear