Once your Sukanya Samriddhi account has completed 21 years, you can withdraw the balance along with interest. When the account matures, the total balance and the accrued interest will be paid out to the beneficiary. You won't be required to pay any withdrawal tax. You'll need to submit a withdrawal application form, proof of identity, proof of citizenship, and residence. However, if after 21 years you don't withdraw the balance, the corpus won't earn any interest.