The single most expensive mistake businesses make when changing Google Ads agencies is letting the new agency build a fresh account. In the handovers we have run and audited, that one decision costs six to twelve weeks of degraded performance and buys nothing in return. Keep the existing account. It carries conversion history, Smart Bidding learning, Quality Score history and audience lists that took months to accumulate, and none of it transfers to a new account ID. Starting clean is also, conveniently, the fastest way to erase the evidence of whether the previous agency was doing anything useful.
Quick reference:
- Never start a new account unless the old one carries a policy suspension you cannot lift
- What you must own: admin access to the Google Ads account, the GA4 property, Google Tag Manager, Merchant Center and Search Console
- What never transfers to a new account: conversion history, bid strategy learning, audience lists, Quality Score history, historical benchmarks
- Ownership check that takes 60 seconds: find the 10-digit customer ID, then confirm at least one person at your company has admin access to it
- Expected transition dip: 2–4 weeks of noisier results while the new team learns the account, not a rebuild
- Worst time to switch: the four weeks before your peak trading season
Who actually owns your Google Ads account?
Whoever holds admin access does, regardless of who built it or who pays the invoices. This is the part most businesses get wrong. An agency managing your account through a manager account — an MCC, in Google’s terminology — has access to it, but that is not the same as owning it. The account is a separate entity with its own 10-digit customer ID, and the link between it and the agency’s manager account can be removed without affecting anything inside the account.
The problem case is different: the agency created the account under their own manager and never gave anyone at your company admin access. Then, in practice, they control it. You can request access, and Google’s manager account documentation describes how links and permissions work, but if nobody on your side has ever held admin rights the process depends heavily on the outgoing agency’s cooperation.
Check it before anything else. Open the account, find the customer ID at the top of the interface, then look at the users list and confirm at least one email address at your own domain has admin — not standard, not read-only. If it does not, that is the first thing to fix, and it is easier to fix while the relationship is still cordial.
What do you lose if you start a new account?
Four things, and all of them are expensive. Conversion history, which is what Smart Bidding uses to predict outcomes: a new account bids blind for weeks. Bid strategy learning, meaning every campaign re-enters the learning period simultaneously. Audience and remarketing lists, which have to rebuild their membership from zero over 30 to 540 days depending on the list. And Quality Score history at the keyword and landing page level, which influences what you pay per click from day one.
There is exactly one situation where a new account is the right call: the existing account carries a policy suspension that cannot be appealed successfully. Everything else — bad structure, wrong campaign types, a mess of legacy conversion actions — is fixable inside the existing account, and fixing it there keeps the history. Any agency proposing a rebuild for structural reasons is proposing to destroy an asset to make their own work easier to present. Our Google Ads audit checklist covers what a genuine restructure looks like without touching the account ID.
What needs to transfer, item by item?
The Google Ads account is the obvious one. The ones that get forgotten are where handovers actually break:
Google Analytics 4 — the property must be owned by your company, not by an agency-controlled Google account. Check the account-level users list for an admin at your domain.
Google Tag Manager — the container holds every tracking tag on your site. Losing it means rebuilding conversion tracking from scratch.
Merchant Center, if you sell products, along with the feed source and any feed rules.
Google Search Console, which is frequently registered under whoever built the site.
Call tracking numbers. If the agency’s platform owns the numbers, they leave with them, and any offline attribution built on those numbers breaks.
Landing pages. If the agency hosts campaign landing pages on their own domain or platform, those URLs die when the contract ends. This is the item that most often turns a clean handover into an emergency.
Reporting and scripts — Looker Studio dashboards, any Google Ads scripts running in the account, and the data sources they connect to.
Ask for each of these explicitly, in writing, before you give notice. A reasonable agency hands them over without drama; the reaction itself tells you something.
How do you actually hand over access?
Grant before you revoke. Add the new agency’s manager account as a link, confirm they can see and edit what they need, and only then remove the outgoing one. The order matters because an account with no manager linked and no admin user at your company is the scenario nobody wants to be in on a Friday afternoon.
Google’s access levels are admin, standard, read-only and email-only. Your new agency needs standard at minimum and usually admin to manage billing and linked products; you should retain admin permanently and never hand over your only admin seat. Linking a manager account is a request-and-accept process documented in Google’s manager account linking guide, which means both sides have to act — so do it while the outgoing agency still has a reason to be helpful.
Billing deserves its own check. If the agency has been paying with their own card and invoicing you, the payment profile belongs to them, and the account will stop serving when that card is removed. Moving to your own payment method is straightforward but it is not automatic, and discovering it mid-transition means paused campaigns.
When is the worst time to switch?
The four to six weeks before your peak season. Retailers should not change agency in late October, tax-adjacent businesses should not change in May, and nobody should change in the fortnight before a product launch. Transitions produce two to four weeks of noise even when they go well, and spending that noise during the period that funds your year is an unforced error.
The other bad moment is immediately after a large restructure by the outgoing agency, because you inherit campaigns still in learning and cannot tell what is transition effect and what is their work. If a restructure has just gone live, either wait three weeks for it to stabilise or accept that the first month’s data is unreadable.
Give the incoming team a documented baseline before they touch anything: 12 months of spend, conversions, cost per acquisition and revenue by campaign, exported. Without it, every later conversation about whether things improved becomes an argument about which numbers to use.
What should the first 30 days look like?
Week one is read-only. A competent agency audits before it edits: account structure, conversion actions and whether they are counting what the business cares about, search terms, wasted spend, tracking integrity. Any agency making bulk changes on day two is not working from evidence, and you will never be able to separate their impact from the transition.
Weeks two and three are for the fixes that do not disturb bidding: negative keywords, obviously broken tracking, budget reallocation away from proven waste, ad copy. Structural changes and bid strategy changes come after, and ideally not all at once, because every one of them resets learning. The reasoning is the same one we cover in our Smart Bidding guide — bid strategies need stability to produce evidence.
By day 30 you should have received a written account of what was wrong, what changed, what is planned, and the baseline they will be measured against. If the first month produces only a dashboard, you have swapped one reporting relationship for another. Our guide to telling whether a Google Ads agency is any good covers the signals worth watching after the transition.
What are the red flags in an outgoing agency?
Refusing admin access, or granting it only after notice is given, is the clearest. Others: campaign landing pages hosted on the agency’s domain; call tracking numbers registered to them; a “proprietary platform” that turns out to be where your conversion tracking lives; and conversion actions configured so that one form submission counts as three conversions.
That last one is worth checking specifically, because it is the most common way reported performance is inflated. Count the conversion actions marked as primary, then compare the total conversions reported to the actual number of leads or orders your business received that month. A gap of 30% or more usually means duplicate counting rather than a measurement subtlety — a pattern we describe in detail in our conversion tracking guide.
None of this means the outgoing agency acted in bad faith. Plenty of these situations are just accumulated shortcuts. But they are your problem to untangle, so find them before the notice period starts rather than after.
Frequently asked questions
Can my agency stop me accessing my own Google Ads account? If they created the account under their manager account and never gave anyone at your company admin access, they can make it difficult in practice. The account still exists independently of their manager account, but regaining control without a cooperative outgoing agency can take time and Google support involvement. This is why the ownership check matters before you give notice, not after.
Should the new agency rebuild my account from scratch? Almost never. Rebuilding inside the same account is fine and often necessary; creating a new account ID is what destroys value. The only genuine exception is an unappealable policy suspension. If a rebuild is proposed for any other reason, ask specifically what cannot be achieved within the existing account — the answer is usually nothing.
How long does a Google Ads agency handover take? Access transfer takes a day if the paperwork is prepared. The performance transition takes two to four weeks, and a further four to eight before changes made by the new team produce readable results. Budget for six to ten weeks before judging the new relationship on outcomes, and longer for businesses with long sales cycles.
What notice period do Google Ads agencies usually require in Australia? Thirty days is the most common, with some contracts at 60 or 90. Read the termination clause for two things beyond the notice period: who owns the assets created during the engagement, and whether there is an exit fee or a data-handover charge. Both are negotiable before you sign and rarely negotiable afterwards. Typical contract structures and fees are covered in our Google Ads management cost guide.
Will performance drop when I change agency? Expect two to four weeks of noisier results — not necessarily worse, but harder to read — because bid strategies respond to changes in the account and the new team is still learning your business. A sustained drop beyond six weeks is not a transition effect, it is a new problem. Keeping the same account ID is what stops a temporary dip from becoming a three-month rebuild.
Can I run a new agency alongside the old one for a month? Not in the same account, and not usefully in parallel accounts. Two teams making changes to the same campaigns produce results neither can interpret, and splitting budget across duplicate accounts means both bid into the same auctions against each other. A clean cut with a documented baseline works better than an overlap, and a paid audit from the incoming agency before the switch gives you the comparison you are actually looking for.
A Google Ads account is an asset with accumulated value: history, learning, audiences and evidence. Changing agency should transfer that asset intact, and the handovers that go badly are almost always the ones where nobody checked who owned what until the notice period had already started.
Do the ownership check this week, whatever you decide about your current agency. If you would like a second opinion on what your account is actually producing before you move, get in touch — we will tell you plainly whether a change is warranted.