How to Choose a Google Ads Agency: What to Check Before You Sign

Choosing a Google Ads agency decides whether your ad budget works toward sales or disappears into campaigns nobody outside the agency understands. The difference between a good partner and a mediocre one rarely shows up in the first sales call — it surfaces two or three months in, when you need to pull data from the account or ask why the campaign isn't growing. Below are concrete criteria you can check before you sign anything.
Who Actually Runs the Campaign — You or the Agency
A Google Ads campaign should run on an ad account registered to your company, with the agency getting manager-level access — not on the agency's own account, where your brand is one of many clients under its client center (MCC). That difference has real consequences: if the agency owns the account, ending the relationship means losing months of campaign history, conversion data, and auction quality score — the next agency starts from zero.
Checking this takes five minutes: ask for access to a Google Ads account (ads.google.com) registered to your company email, not the agency's inbox. A refusal, or an explanation that “it's just more convenient this way,” is a warning sign, not a technical detail.
What It Costs to Run a Google Ads Campaign — Pricing Models
Google Ads agencies typically charge under one of three models: a percentage of ad spend (usually 10–20% for accounts up to roughly $5,000 a month, dropping as budgets grow), a flat monthly retainer (usually $500–2,000, regardless of ad spend), or a hybrid model — a lower base fee plus a bonus tied to a result, such as cost per lead falling below an agreed threshold.
Any of these models can work well — the problem shows up when an agency can't clearly explain what you're paying for, or when a percentage fee grows alongside the budget without any added scope of work. A bigger budget doesn't automatically mean more optimization work.
| Model | How it works | When to choose it |
|---|---|---|
| Percentage of spend (10–20%) | Fee grows together with ad spend | Growing budgets, less predictable costs on the client side |
| Flat retainer ($500–2,000/mo) | Fixed amount regardless of ad spend size | Stable, predictable ad budget month to month |
| Hybrid (base + result bonus) | Lower fixed fee plus a bonus for hitting an agreed KPI | Accounts with a clearly measurable goal, e.g. cost per lead |
Does Google Partner Status Actually Mean Anything
A Google Ads certification and Google Partner badge confirm an agency knows the platform's interface and fundamentals — they don't confirm it can run a profitable campaign in your industry. Partner status requires maintaining minimum client spend and passing staff certification exams — it doesn't measure optimization quality or conversion tracking accuracy.
Experience in your specific business model tells you more. An agency that has run e-commerce accounts for years will structure a Performance Max campaign differently than one specializing in B2B leads. Ask directly for two or three accounts in your industry, and how budget was split across campaign types there.
How to Verify an Agency's Case Studies and Reviews
The most reliable way to check an agency's reputation is on third-party platforms with reviews verified by paying clients, like Clutch.co, where the agency can't moderate content itself. What matters isn't just the average rating, but the number of reviews and whether they're from the last 12 months or several years old.
- Ask to talk to one current client in a similar industry — an agency with real results to show usually says yes
- Check whether a case study shows concrete numbers (cost per conversion, ROAS, number of leads) instead of vague claims about "increased visibility"
- Ask how long that client has worked with the agency — length of the relationship says more than a single good month
- Check the agency's Clutch.co and LinkedIn profile for whether case studies and communication are current

What to Check in a Google Ads Agency Contract
A Google Ads agency contract should clearly state the notice period (typically 1–3 months), what scope of work the monthly fee covers, and who owns the creative assets and account access after the relationship ends. A contract with no clear notice period, or one that auto-renews for another year, is worth reading more carefully.
- Notice period — typically 1–3 months; a longer one only makes sense in exchange for something, like a lower fee
- Account and data ownership — who keeps admin access after the relationship ends, and whether conversion data gets exported
- Scope of work — whether the fee covers Search only, or also Shopping, Performance Max, Display, and landing page optimization
- Industry exclusivity — some agencies won't work with direct competitors in the same category; worth asking outright
- KPIs written into the contract — if an agency commits to a specific result, it should be written down with a definition of how and when it's measured
Red Flags That Should Make You Look Elsewhere
Three warning signs come up most often: no access to your own Google Ads account, a guaranteed result (like "we guarantee 5x ROAS") promised before the agency knows your industry and account history, and no regular reporting beyond an automated email from the ad platform.
Questions Worth Asking on the First Call
The seven questions below let you tell, in a 30-minute call, whether an agency understands your business model or is selling the same package regardless of client industry.
- Which Google Ads account will the campaign run on, and who has access to it after the relationship ends?
- What does the fee structure look like, and what's included — optimization, reporting, consultations?
- How many accounts in my industry or a similar business model do you currently run?
- How do you track conversions — server-side tracking, or just the standard Google Ads tag?
- How often, and in what format, will I get a results report?
- What's the contract's notice period, and what happens to the account after it ends?
- Can you show a sample monthly report from another account, with client data blurred out?
Before signing a contract for Google Ads management, go through this list point by point — a good agency will answer every one of these questions without hesitation, because that's how it already works day to day. At Zest, we always run campaigns on the client's own account, with server-side conversion tracking and reports that show sales, not just clicks; if you're weighing a change of agency, let's talk about your account — as a digital marketing agency we start every conversation with a free review of your current campaign.
See also: the ranking of Google Ads agencies in Poland and how much it's actually worth spending on Google Ads and Meta Ads in 2026.
FAQ
Q.Which Google Ads account should the campaign run on?
The campaign should run on an ad account registered to your company, with the agency getting manager-level access. If the agency owns the account, ending the relationship means losing campaign history and months of conversion data.
Q.How much does it cost to have an agency run a Google Ads campaign?
Typical models are a percentage of ad spend (10–20% for accounts up to roughly $5,000 a month, dropping as budgets grow) or a flat monthly retainer of $500–2,000, depending on scope of work and the number of campaign types.
Q.Does Google Partner status guarantee good campaign quality?
No. Google Partner status confirms minimum client spend and passed staff certification exams, but doesn't measure optimization quality or conversion tracking accuracy. Experience in your specific industry and business model matters more.
Q.What's a standard notice period for a Google Ads agency contract?
Typically 1–3 months. A contract that auto-renews for another year, or has no clearly stated notice period, is worth reading more carefully.
Q.What are the most common red flags when choosing a Google Ads agency?
No access to your own ad account, a guaranteed ROAS promised before the agency knows your industry and account history, one campaign template copied across different clients, and reporting limited to a panel screenshot with no link to sales.

Talked to dozens of companies switching Google Ads agencies — usually because of no access to their own ad account and reports disconnected from actual sales.
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