Switching Marketing Agencies? What We Found When We Took Over a Client's Google Ads and Website

When you’re switching marketing agencies, plan the handover as carefully as you chose the agency. Before anyone changes a campaign, make sure your business owns every account and the old supplier’s access is gone, confirm your website is still telling Google Ads which clicks became enquiries, redirect every old page address, and have the new agency audit what’s there before they touch it. The damage from a messy handover is usually quiet: the ads keep running, the spend keeps going out, and the numbers underneath stop meaning anything.

This post comes from a Google Ads account and website we took over at the end of August 2026 for a passenger transport client. I’m not going to write about the client’s business or the agency before us. What’s useful is the pattern, and it applies whether you sell airport transfers, plumbing, physio or pallets.

Spend Stayed Steady While Measurement Collapsed

The ads kept running. Spend stayed steady from month to month, people kept clicking, and enquiry forms kept arriving.

Underneath, the account had gone blind. The website had stopped telling Google Ads which clicks turned into enquiries. When we audited the account on 31 August, every conversion action in it had either been deleted or had never recorded a result. The quote value Google Ads recorded was strong in June and had fallen to almost nothing by August, while spend stayed flat.

That’s what makes broken tracking expensive. A Google Ads account doesn’t stop spending when its conversions stop. It keeps bidding, just without the one signal that tells it which searches are worth paying for.

Four Failures, and How Each One Led to the Next

What I found most instructive is that there wasn’t one failure. There were four, and the later problems came from people reacting to the earlier ones.

1. Mid-May: the original conversion tag stopped recording for nine days, while spend carried on.
2. Mid-July: the quote tracking stopped on its own. Enquiry forms kept arriving at the same daily volume, so the business was still getting work. Google Ads just stopped hearing about it.
3. Mid-August: the website was rebuilt with a completely different tracking setup.
4. Then: a set of 51 keyword exclusions had been added to stop the ads showing to people searching for buses, trains and flights rather than a shuttle. Six days later they were deleted, and after that every campaign was paused.

Read from inside an account with no working conversions, the ads looked as if they were failing. The filters came out, then the whole account was switched off. But the ads hadn’t stopped working. The measurement had.

This is the opinion I’d most like owners to take away: when Google Ads “stops working” after a rebuild or a change of supplier, check the measurement before you judge the ads. And while tracking is blind, nobody changes campaigns. Not the old agency, not the new one, not you. Every decision made from a blind account is a guess, and guesses have a habit of undoing the things that were working, which is what happened to those exclusions.

Tracking Lives Inside Your Website

The client’s website had been rebuilt three times in 2026, on three different platforms. Conversion tracking was lost at each rebuild and never reconnected.

This catches owners out, because the conversion settings sit inside Google Ads, so it feels like that’s where tracking lives. The code that actually says “a quote form was just submitted” or “someone tapped the phone number” lives on the website. Replace the website and you replace that code. Whoever builds the new site has to rebuild the tracking and then prove it works, every time, even when nobody touched the ads.

If your web designer and your ads manager are different people, this is the job that falls between them. Put in writing whose job it is before the rebuild starts.

Enquiries Were Being Counted as Purchases

When we looked at what the booking code was actually sending, it sent the same “purchase” signal for an unpaid enquiry as for a completed payment, with the value set to zero. Two separate Google Analytics properties were in use as well. Page visits went to one and phone clicks went to the other, so neither held the full picture.

Google Ads learns from the signals you give it. If a price question and a paid booking send the same signal with the same zero value, it has no way to favour the searches that lead to paying customers. Measure enquiries and paid bookings as separate things, in one analytics property, and label each one for what it is.

”Conversion Value” Is Not Revenue

The value recorded in the Google Ads account was the total of fares quoted on enquiry forms, rather than money received. A quote for a trip that never went ahead counted the same as one that did.

So when that value collapsed between June and August, it would have been easy to put a dollar figure on what the broken setup had cost. We told the client plainly that we would not present a lost-revenue figure we couldn’t evidence. The tracking was broken, so any number would have been a guess presented as a finding.

Take that into any agency conversation, including one with us. If someone quotes you revenue from an ad platform’s value column, ask what that value actually measures. And if a new agency’s pitch leans on how much the last one “lost” you, ask how they know.

A Handover Isn’t Finished Until the Access Is

After the handover, the previous agency’s manager access to the Google Ads account was still active, and changes were still being made to the account days before our audit. Our first recommendation, ahead of any fix, was to remove that access. It has since been removed.

I’m not suggesting anything about why it was still there. Leftover access is easy to miss when nobody owns the offboarding. But you can’t repair an account that two parties can change, and you can’t read its history clearly if you don’t know whose edits are whose.

The bigger point is ownership. Your ad accounts, analytics, tag manager, domain, hosting and website admin should be owned by your business, under your login, with suppliers added as users you can remove. If a supplier owns the account and lets you in, that’s the wrong way round. Our guide to comparing web design quotes covers the website side of ownership in more detail.

Check Where the Ads Send People, and Who They Reach

The rest of the audit turned up four more problems, each worth checking in your own account:

• Dead landing pages. Both pages the old search ads pointed at had been removed without redirects and returned errors. Every campaign sent people to the homepage rather than the page for the service they had searched for.
• People interested in an area, not people in it. Eight of nine campaigns were set to also reach people who had shown interest in the service areas, rather than only people actually in them. Google’s advanced location options help page lists presence or interest as the default and recommended setting, so a campaign ends up with it unless someone changes it. For a business that physically collects its customers, that setting pays for clicks from people who can’t use you. Two campaigns also excluded Auckland entirely, which works against a shuttle that serves Auckland Airport.
• Campaigns competing with each other. Seven Performance Max campaigns ran over the same period and competed for the same searches.
• Irrelevant searches. A large share of search spend went on people looking for buses, flights, trains and taxis, which is what the deleted exclusions had been there to stop.

The Order We Fixed It In

The sequence mattered more than any single fix. This is the order we used:

1. Secure the accounts. Remove the old access and confirm the business owns everything.
2. Rebuild tracking, with enquiries and paid bookings measured separately.
3. Build a dedicated landing site around quote requests, with the same tracking on every page, so a future edit can’t quietly break it on one page and not the others.
4. Redirect the old URLs to their new equivalents.
5. Switch the ads back on only once a real enquiry was confirmed recording in Google Ads.
6. Consolidate the campaigns, from seven Performance Max campaigns to one.

Notice that the campaign changes come last. Until step five, nothing in the account could tell us whether a change helped or hurt.

The result: 400+ quote requests in the first three weeks after relaunch, and 28% of Google Ads visitors requesting a quote. That 28% comes from a site built around a single quote form, so don’t treat it as a benchmark for a general website. What matters more is that we can stand behind it, because the tracking that produced it was tested before the ads went back on.

A Checklist for Switching Marketing Agencies

Use this whether you’re changing agencies, bringing marketing in-house, or rebuilding your website with the people you already have.

Before you give notice

• List every account: Google Ads, Google Analytics, Google Tag Manager, Search Console, Google Business Profile, Meta, your domain registrar, hosting, website admin, and any form or booking tools.
• Check who owns each one. It should be your business, not a supplier.
• Export or screenshot the last twelve months of performance while you still have full access.
• Count a month of real enquiries from your inbox and phone. That’s your ground truth for checking any report that comes later.

On handover day

• Remove the old supplier’s access to every account, or reduce it deliberately if they’re still doing part of the work.
• Change any shared passwords.
• Ask for a written list of what’s running: campaigns, tracking tags, automations, and anything billed to your card.

Before anything changes

• Have the new agency audit the account and tell you what they found before they change anything.
• Submit a test enquiry on your website and confirm it appears in Google Ads and Google Analytics as an enquiry, not a sale.
• Compare the enquiries Google Ads reports with the ones you counted yourself. If they disagree badly, fix tracking first.
• Freeze campaign changes until tracking is proven.

If the website is being rebuilt

• Map every old page address to its new one before launch. Google’s site move guidance recommends exactly that, and says permanent (301) redirects don’t cause a loss in PageRank.
• After launch, open every page your ads point to and check it loads.
• Re-test every conversion on launch day from a phone: forms, phone taps, bookings.
• Test again a week or two later. In this account, the quote tracking stopped on its own in July with no rebuild at all, so launch-day checks aren’t enough on their own.

Before You Blame the Ads

If your Google Ads enquiries dried up after a switch or a rebuild, the ads may be fine and the reporting blind. If the enquiries really have stopped arriving in your inbox, that’s a different problem, and our post on a website getting traffic but no enquiries walks through the checks in order.

If you’re still deciding who to switch to, our guide on how to choose a digital marketing agency covers the questions for the first call. Add one more: “What will you check before you change anything?” A good answer starts with access and tracking.

You can read the full case study for how the relaunch came together. We look after Google Ads management for NZ businesses, and if you’re about to change agencies or rebuild your site, get in touch and we’ll check your account ownership and conversion tracking with you before anything moves.