Control spend with shared budgets or isolated campaign caps. Understand overdelivery and when to split pools to protect pacing.
What is a shared budget in Google Ads?
A monthly spend limit that pauses billing
A bid cap set at the keyword level only
A lifetime cap applied to one ad group
A single average daily budget shared across multiple campaigns
Which campaigns are incompatible with shared budgets per Google?
Brand campaigns with portfolio bid strategies
Any Search campaigns using manual CPC
Any campaigns linked to a shared library
Campaigns using a total (lifetime) budget
How does overdelivery interact with daily budgets?
Overdelivery only applies to Smart campaigns
Google may spend up to 2× the daily budget on high‑opportunity days but averages to the monthly target
Spend is capped at 1.05× per day with no monthly smoothing
Overdelivery charges are always refunded the same day
When might a shared budget be preferable to individual campaign caps?
When you want to disable auction‑time bidding
When each campaign must never exceed a fixed daily maximum
When you need strict budget isolation for tests
When several campaigns pursue the same goal and demand varies day‑to‑day
Which API setting controls whether a campaign budget can be shared?
Turning on Budget Explorer in Tools
Setting CampaignBudget.explicitly_shared to true
Editing the account’s payment profile
Setting Campaign.maximize_conversions.target_cpa to 0
Which pacing risk increases when dissimilar campaigns share one pool?
One campaign can cannibalize spend and starve others
All campaigns receive equal impression share by default
Costs per click drop uniformly across all campaigns
Shared budgets disable overdelivery entirely
For strict experiment control, which choice is safer?
Rely on overdelivery to balance groups
Use separate campaign budgets with capped daily amounts
Pause eligible auctions to keep parity
Use one shared budget so the algorithm can reallocate
Which statement about monthly spend protection is accurate?
Charges won’t exceed average daily budget × 30.4 over a month
Monthly protection applies only to video campaigns
Monthly protection disables shared budgets
Charges won’t exceed daily budget × 7 per week
What’s a practical sign to split a shared budget into separate caps?
One campaign consistently consumes the pool and others under‑deliver
ROAS variance is zero across campaigns
Every campaign has identical CPCs
All campaigns meet impression share targets
Which lever helps avoid overspend mid‑month when using shared budgets?
Turn off all extensions to reduce CPC
Lower the shared daily amount and add per‑campaign bid/target constraints
Disable automated bidding entirely
Set budgets to zero and rely on overdelivery
Starter
Good start—review shared vs. campaign budgets and overdelivery rules.
Solid
On track—split pools when campaigns cannibalize and protect tests with caps.
Expert!
Excellent—your pacing isolates tests and hits monthly targets precisely.
