The daily budget is the amount you are willing to spend on your campaign each day.
Amazon has updated how daily budgets are allocated. For campaigns created after March 27, 2023, if a campaign spends less than its daily budget, the unused portion can be used to increase the daily budget by up to 100% on other days within the same calendar month. For campaigns created before March 27, 2023, this increase is capped at 25%.
You have the option to opt-in for the 100% daily budget increase or to stick with the 25% increase for all your campaigns. To adjust this setting, go to your Ad Console and navigate to Sponsored Ads → Campaign Manager → Settings.
🚨 Note: By default, all campaigns created after March 27th will have a 100% budget rollover, while those created before this date will have a 25% rollover. You can choose to apply a 25% or 100% rollover to all your campaigns, but once you make this selection, you cannot revert to having a mix of 25% and 100% rollovers. 🚨
Regardless of your choice, by the end of the month, your total spend will not exceed your daily budget multiplied by the number of days in that month.
For example, if your daily budget is $20 and the month has 30 days, the maximum amount you’ll spend that month is $600.
Once your daily budget is reached, your campaign will pause until the following day when the budget resets. For more detailed information, you can refer to Amazon's guidelines here.