The Switching Tax
Changing Google Ads agencies is not free. Even when your current agency is underperforming, the transition carries real costs that should be weighed against the expected improvement.
This is not an argument against switching. It is an argument for switching with your eyes open.
The Direct Costs
Learning period: A new agency needs 4-8 weeks to understand your account, your products, and your commercial context. During this period, performance typically dips 10-25% as they adjust strategies and rebuild campaigns.
Setup fees: Most agencies charge onboarding or setup fees ranging from one to three months' management fee. This is cash out before any improvement materialises.
Overlapping contracts: If your current agency has a notice period and your new agency charges from day one, you may be paying double for a month or more.
Data loss risk: If your current agency owns the Google Ads account (some do), you lose all historical data, conversion history, and accumulated quality scores. This is the most expensive risk and the most avoidable.
The Hidden Costs
Internal time: Your team will spend 20-40 hours onboarding a new agency: briefings, access provisioning, commercial context sessions, and creative asset handovers.
Strategic disruption: Your current campaigns, however imperfect, are generating revenue. Restructuring them introduces uncertainty. Revenue may drop before it improves.
Relationship building: Trust takes time. Your new agency will not understand your business as well as your current one for at least 3-6 months. Early recommendations may miss commercial nuance.
When Switching Is Worth It
Despite the costs, switching is the right decision when:
1. Your agency cannot explain your profitability
If they report ROAS but cannot discuss contribution margin, POAS, or unit economics, they are managing a platform, not a commercial outcome. The gap between their reporting and your P&L will only widen.
2. They have never recommended spending less
An agency that only recommends increasing budget is optimising for their revenue, not yours. Especially if they charge a percentage of spend.
3. Performance has plateaued despite market growth
If your category is growing but your Google Ads results are flat, the problem is likely strategic, not market-driven. Fresh perspective and methodology can unlock the next level.
4. Communication has become defensive
When your questions about performance are met with excuses rather than analysis, the relationship has broken down. Good agencies welcome scrutiny.
5. You have outgrown their capability
The agency that was right for you at £10,000 monthly spend may not be right at £50,000. Different scales require different expertise, tools, and commercial sophistication.
How to Switch Well
1. Own your Google Ads account
Before anything else, ensure you have admin access to your own Google Ads account. This is non-negotiable. Your data belongs to you.
2. Document your current state
Export campaign structures, bid strategies, audience lists, and negative keyword lists. This accelerates the new agency's learning period.
3. Set realistic transition expectations
Performance will likely dip during transition. Set a 90-day window before judging the new agency's impact. But establish clear benchmarks they should hit by day 30, 60, and 90.
4. Define success commercially
Do not hire a new agency to improve your ROAS. Hire them to improve your contribution margin, your customer acquisition efficiency, or your profit per pound spent. Measure what matters.
5. Run a diagnostic first
A credible agency will audit your account before proposing a strategy. If they promise results without seeing your data, they are selling, not diagnosing.
The Bottom Line
Switching agencies costs money and time. But staying with the wrong agency costs more. The key is to switch for the right reasons, at the right time, with the right preparation.
And if your new agency cannot explain the cost of switching as honestly as this article does, that tells you something about how they will communicate once they have your account.