Google AdsThe four guardrails
- Daily cap: the most the account may spend in one day, in the client's currency.
- Monthly cap: the total for the month, with the planned budget and the reserve set aside.
- Change limit: the largest budget move one person may make alone, as a share of the current budget.
- Alert level: the point where someone is told before a cap is reached, not after.
Setting the numbers
Start from the approved monthly budget, not from last month's actual spend. Set each cap against the break-even ROAS for the product group, not against a round number.
- Keep a reserve for the last days of the month. Agree its size with the client and write it down.
- Set the change limit low enough that one mistake costs a day, not a month.
Made-up scenario: a store has a made-up monthly budget of 30,000 in its currency and a reserve of 3,000. The alert fires on the 20th, when the account is ahead of plan. On the 21st the media buyer pauses one ad set and logs the reason.
Who can change a guardrail
- Only the account lead changes a cap, and every change is logged with the old value, the new value, the reason and the approval.
- The change follows the ad change approval workflow.
Checking them each day
- Spend against the daily cap, read from the platform at the time of the check, and any change above the change limit with its approval.
A guardrail nobody checks is only a sentence in a document. Put the check into the five-minute daily account check.
