If you have a naira wallet, by default you get notified when your wallet balance is low as low as ₦500.
You can, however, set a threshold on your account that automatically sends you a notification when your balance gets to a certain amount, that way you are able to top up before you run out of funding.
Here is how to set a threshold on your account:
Log in to your dashboard here .
on the left pane, click on Billings
On the billings page, click on Manage threshold.
Input your preferred amount and click on set limit.
That way you get a notification once your balance gets to that amount and you can top up before you run out of funding.
Please note that the notification goes to the primary email address on your account.