If you want to return your old naira notes, then make sure to read this article
There's an outcry about the lack of cash in Nigeria. You can see the riots and damages angry mobs are doing in banks and other financial institutions because of how bad things have become.
Let's look at it this way. People can't pay for transportation and have to trek to work. They can't pay for food except for transfers, and since cash is essential to everyone, not everybody accepts transfers.
Nowadays, even people in major markets like Onitsha main market don't sell anymore because nobody has cash. These are just a few of the problems that people face out here. If you include the high price of petrol, then you have a riot brooding.
To help reduce the effects of this transition, CBN has launched a portal for the collection of old naira notes. The directive from the government is that cash of a maximum of NGN500,000 will be accepted back from citizens.
To do this, you need to signup on to the CBM portal here.
After signing up, you can then go to the bank with your cash(not more than NGN500,000) to deposit.