About max CPC bids

Max CPC is the highest amount that you're willing to pay for a click on your ad. (Max CPC is often called a bid.) That is, if you set max CPC to 3.00, then you could pay up to 3.00 if a customer clicks your ad. Note that often you'll pay less than the max CPC because in each auction, the most you'll pay is what's needed to rank higher than the advertiser immediately below you. 

Bid adjustments may increase max CPC

If bid adjustments are set in a campaign or ad group, you could pay more than the max CPC for a click on an ad. A bid adjustment can increase or decrease the default bid to target any of the following items. Note that supported bid adjustments vary by engine account type.

• Mobile devices
• Tablet devices
• Desktops
• Google Ads only bid adjustments
  • Remarketing targets 
  • Location targets
  • Demographic targets
    • Age group targets
    • Gender targets

Inheriting max CPC

By default, product groups and product targets inherit max CPC from the parent ad group. Keywords also inherit max CPC from the ad group if you don't specify a value for the keyword's max CPC property when you create the keyword. For example, the following line creates a keyword that inherits the max CPC setting from the parent ad group:
home loan, broad, , https://example.com/loan

Bid strategies and max CPC

Bid strategies automatically review and potentially change the max CPC for biddable items multiple times a day. This means that any biddable item that is managed by a bid strategy will no longer inherit the max CPC setting from the parent ad group.

If you need to temporarily override the max CPC set by a bid strategy, you can change the max CPC setting. 

Different ways to change a bid

Because biddable items can inherit max CPC from the ad group, there are a few different ways to change a bid:

• Change the ad group's max CPC
  Any biddable item that inherits the ad group's max CPC will automatically use the new max CPC. Note that biddable items in a bid strategy no longer inherit max CPC from the ad group, so changing an ad group's max CPC will not affect bids for items in a bid strategy.
• Change or set max CPC for a biddable item
• Set a biddable item to inherit max CPC from the ad group
• Use a bulksheet to change max CPC

You can also use automated rules to change max CPC.