Limit AdWords Overdelivery to Any Amount You Want

Google announced that daily budgets will now be able to overdeliver up to 100% rather than 20% as had been the case since the earliest days of AdWords.

Overdelivery allows Google to help advertisers meet monthly budget targets by making up for slow traffic days by spending more money on high volume days. They assume that advertisers will divide their monthly budget by 30.4, and set this as the daily budget. Then when there may not be a whole lot of traffic on Saturdays and Sundays, Google can exceed the daily budget on Mondays and Tuesdays when there might be more people looking for what the advertiser sells.

Here's Google's announcement:

To truly control budgets they way you need, you'll probably want to use tools, automations, and AdWords Scripts. Here's a very basic script that lets you enforce a more strict overdelivery for a campaign. The script assumes that your daily budgets are the baseline of what you'd like to deliver. Use the setting 'allowedOverdeliveryPercentage' to control a maximum spend for the day by setting a value between 0% and 100%. The script fetches every active campaign's daily budget and accrued cost for the day. If the cost exceeds the daily budget + the allowed percentage of overdelivery, it will label that campaign and pause it.

Important Notes:

• Remember to use another automation to re-enable all paused campaigns during the first hour of every day. You can look for campaigns that have the label set by the script and re-enable those. 
• The script can be run once per hour so you may still exceed the total cost until the next time the script runs. 
• The script doesn't deal with shared budgets.
• The script doesn't deal with shopping and video campaigns. Making it work for those is really easy, you just have to update the campaigns call to use the video and shopping methods for getting campaigns.

If you need more control over budgets, and you don't want to do any coding, consider our prebuilt scripts available as part of an Optmyzr subscription (Optmyzr is my company).

/******************************************
*
* Version 1.0 
* Created By: Frederick Vallaeys
* FreeAdWordsScripts.com
******************************************/

function main() {
  
  var allowedOverdeliveryPercentage = 0.2; // set percentage as decimal, i.e. 20% should be set as 0.2
  var labelName = "paused by overdelivery checker script";
  
  AdWordsApp.createLabel(labelName, "automatic label needed to reenable campaigns");
  
  var campaigns = AdWordsApp.campaigns()
   .withCondition("Status = ENABLED")
   .withCondition("Cost > 0")
   .forDateRange("TODAY");
  
  var campaignIterator = campaigns.get();
  
  while (campaignIterator.hasNext()) {
    var campaign = campaignIterator.next();
    var campaignName = campaign.getName();
    var budgetAmount = campaign.getBudget().getAmount();
    var costToday = campaign.getStatsFor("TODAY").getCost();
    
    if(costToday > budgetAmount * (1 + allowedOverdeliveryPercentage)) {
      Logger.log(campaignName + " has spent " + costToday + " which is more than allowed.");
      campaign.applyLabel(labelName);
      campaign.pause();
    } else {
      Logger.log(campaignName + " has spent " + costToday + " and can continue to run.");
    }
  }

}