Google Ads has quietly confirmed a rule many search advertisers never saw. For Search campaigns using Display Expansion, the system did not send all unspent Search budget to the Display Network—it applied what the Help Center calls “a 50% budget allocation applied in the backend.”
That hidden limit disappears in February 2027, when Search campaigns with Display Expansion move to channel prioritization.
What changes in February 2027
The new model turns an invisible split into a visible one. Advertisers can mark the Google Display Network as High or Low priority and add an optional daily budget allocation percentage. Google’s suggested way to recreate the old setup is specific: set the Google Display Network to Low priority with a 50% daily budget allocation.
- Before: a hidden 50% backend allocation.
- October 2026: priority tiers and optional percentage caps start rolling out.
- February 2027: automatic migration; the old allocation goes away.
The disclosure arrives after Google introduced channel prioritization and budget allocation in October 2026. At the time, Google suggested a Low priority Display setting with a 50% allocation for advertisers who wanted to keep their existing setup, but it did not explain why 50% matched. The Help Center page now gives the answer: the platform was already using that figure behind the scenes.
Why the default could surprise you
The risk is not the control, it is the silence. Google’s channel prioritization documentation says channels start at High priority unless someone changes them. That means an account that does nothing after February is not automatically holding the old 50% split. Spend could shift across Google Search, search partners and the Display Network.
There is also an edge case: the related channel prioritization page says Display will stop serving on Search campaigns using the Target Impression Share bid strategy. Campaigns built on impression share goals lose that Display route entirely.
The Help Center page itself carries no publication date. It describes options available as of October 2026 and an automatic transition starting in February 2027. It does not say whether the migration happens on a single date or in stages, or whether Google will write a 50% Low priority configuration into migrated campaigns.
What to check now
Audit two places before the migration: account-level channel prioritization defaults and campaign-level network settings. If current performance depends on the old split, set the Google Display Network to Low priority with a 50% daily budget allocation. If you prefer a different mix, set an explicit cap now.
One caution from Google’s own documentation: the percentage limit works on a best-effort basis and daily spend may occasionally exceed it. Treat it as a targeting mechanism, not a hard guarantee.
For context, Google’s page still repeats performance claims of up to 15% more conversions at similar CPA and an average 14% more conversion value for value-based bidding, but without date ranges, samples or method. Those ceilings are Google’s numbers and are not independently verified.
The change lands in a year when Google has reorganized Display inventory itself: standalone Display campaigns are being folded into Demand Gen, where the Display Network becomes an opt-in channel.
Source: PPC Land
