When you're approved for monthly invoicing, you’ll be assigned a credit line. Using this amount you can calculate the maximum amount you can use as your average daily budget. This is a good way to distribute your campaign costs over a certain time period. Here's how you'd use one:
Let's say that you have a Google Ads account with two campaigns, and you want to spend a total of $10,000 for the 30-day month. To make sure that this $10,000 lasts the entire month, first decide how much you want to spend on each campaign. Suppose that you want to dedicate $7500 to campaign No.1 and $2500 to campaign No.2. To find your average daily budget, divide each amount by 30:
$7500 / 30 = $250
$2500 / 30 = $83.33
Following this formula, you'll assign campaign No.1 an average daily budget of $250 and campaign No.2 an average daily budget of $83.33.
Bear in mind that if you'd like to spend $10,000 per month and you have 30 days to pay your bill, your credit line has to be at least $20,000. Why? After the first month, you'll have used $10,000 of your credit line. So, by the time you'll have paid the bill, (i.e. after 30 days), you'll have spent an additional $10,000 with Google for that second month. That's why your credit line has to be at least $20,000.
Your campaign daily costs might go slightly over or under your average daily budget, but you won't be charged more for a campaign than your average daily budget times the number of days in that period. This is known as overdelivery.
When setting your campaign budgets, keep in mind that your credit line will need to cover all your account costs, including:
- The costs accruing in your account(s) each day for which you haven't been billed.
- The costs for which you've been invoiced but haven't yet paid.
- The costs that accrue in your account while your previous month's payment is processed (a minimum of several days).
If you don't spend your average daily budget each day, your monthly costs could be lower than you expect. That's why it's a good idea to check your costs regularly, in case you'd like to raise your bid.
You can view your accrued costs on the Campaigns page. Make sure that you set the date range for an appropriate period, then find accrued costs for each campaign in the last column of the table.