The Australian Securities and Investments Commission fined NAB $10,200 after an investigation found potentially misleading statements about its annuity term deposit.

The deposits are commonly used by retirees as a source of income and are also purchased by retail investors.

The fine relates to the bank's product disclosure statement between June 2013 and August 2014, which stated the fixed interest rate was calculated on the entire principal amount invested. ASIC said the rate applied only to the balance of the principal, which in fact reduced throughout the term of the investment.

NAB has since published a new product disclosure statement.

The sting is the latest in ASIC's campaign targeting corporate advertising this year.

NAB was fined $40,800 in September over its promotion of a $2014 gift card for customers who took out home loans with its online lender, UBank.

ASIC said it was concerned some of the ads did not prominently disclose certain terms and conditions.

Westpac was fined $20,400 over claims made about returns available on an annuity deposit.

ASIC deputy chairman Peter Kell said the watchdog would continue to "take action where we believe entities are not accurately promoting the product they offer".

More than a dozen financial services companies have been fined for making misleading statements this year.