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    European Search Awards 2026 Winner - Best PPC Agency

    Guide / Commercial decisions

    How to switch
    PPC agency
    without losing
    momentum.

    You've decided the answer is yes. The next ninety days will decide whether the switch pays for itself or costs you a trading quarter. Most brands lose momentum in the same three or four places. This is how to stop it.

    Reading time

    10 minutes

    Written for

    Founders and marketing leads mid-way through an agency switch, or thirty days out from starting one.

    The premise

    Switching agencies is a technical event, a commercial event, and a data event — in that order.

    Most transitions treat it as a relationship handover. Two intro calls, a shared Slack channel, a Monday kickoff.

    That is the fastest way to lose a trading quarter.

    The accounts that switch cleanly do three things: they protect ownership of the data, they preserve continuity of the signal, and they delay creativity until the new team has commercial context.

    Everything below is a version of those three ideas.

    Read this twice

    A clean switch is boring in week one and interesting in week six. A messy switch is the other way around — and the second version costs you a trading quarter.

    The playbook

    Four phases. Ninety days.

    Every switch we've run has moved through the same four phases in the same order. Skip a phase and the damage shows up two months later — usually as an unexplained profit drop the new agency can't diagnose.

    Phase / 01

    Days -30 to 0

    Before you sign anything

    The transition starts before you've picked a new agency. If you skip this, you'll spend the first month of the new relationship recreating context that should have been packaged up on day one.

    What to do

    • Confirm you own the Google Ads MCC, GA4 property, Merchant Center, Tag Manager container and Search Console — not the agency.
    • Export a 24-month performance history at campaign, ad group and product level. Store it outside the account.
    • Pull a clean cost file: SKU, COGS, shipping, fulfilment, return rate, category, margin.
    • Document every offline conversion feed, CRM sync, and enhanced conversions setup that currently exists.
    • Ask the outgoing agency for the change log — bid strategy changes, campaign restructures, script edits, feed rules.

    Where momentum dies

    Most brands discover their outgoing agency owns the accounts at exactly the moment they want to leave. Fix ownership first, or the handover becomes a hostage negotiation.

    Phase / 02

    Days 1 to 14

    Continuity, not creativity

    Week one is not the moment to restructure the account. It is the moment to preserve every ounce of learning inside it. Restructures come later, once the new team has commercial context.

    What to do

    • Grant the new agency admin access — never transfer ownership of the MCC.
    • Freeze structural changes: no new bid strategies, no campaign consolidation, no PMax rebuilds.
    • Duplicate conversion tags in parallel before touching the originals. Verify in real time.
    • Confirm enhanced conversions, offline conversion imports and consent mode are firing correctly under the new team.
    • Hand over the cost file, margin data, inventory position and SKU roles in the first onboarding session.

    Where momentum dies

    Rebuilding a working account in week one is the single most common way to blow a switch. Learning phases reset, smart bidding stalls, and revenue drops for reasons that have nothing to do with the market.

    Phase / 03

    Days 15 to 45

    Diagnose before you restructure

    This is where a commercial partner earns their fee. Not by rebuilding what worked, but by identifying what the previous agency couldn't see — because they weren't looking at the P&L.

    What to do

    • Segment performance by SKU role: scale, profit, protect, recovery, gateway.
    • Model contribution margin after ad cost by product group. Find the SKUs that lose money every time they sell.
    • Split reporting between new and returning customers. Set allowable CAC by category.
    • Run a PMax transparency exercise: brand share, prospecting share, asset group contribution.
    • Agree what changes in the next 45 days — and what deliberately stays untouched.

    Where momentum dies

    If your new agency starts restructuring campaigns before they've opened your cost file, you've hired another media buyer. Send them back to the P&L.

    Phase / 04

    Days 46 to 90

    Rebuild on commercial logic

    Now structural changes are earned. Every restructure should trace back to a commercial decision — margin, inventory, customer economics — not a platform preference.

    What to do

    • Restructure campaigns around commercial jobs, not platform conventions.
    • Rebid or exclude structurally unprofitable SKUs identified in the diagnostic.
    • Implement break-even ROAS targets by product group, not a blended account target.
    • Rebuild PMax with asset groups mapped to SKU roles, not seasonal themes.
    • Set the 90-day review agenda around profit, not revenue.

    Where momentum dies

    Momentum is lost when the 90-day review defaults to a ROAS deck. Insist the review opens with contribution margin, payback and inventory movement — the metrics the switch was supposed to fix.

    The data audit

    Eight things to confirm before you tell your current agency.

    The moment notice is served, cooperation drops. Confirm every item on this list before that conversation happens.

    01

    Google Ads MCC ownership

    Your business owns the MCC. Agencies are granted access, never the reverse.

    02

    GA4 property + Tag Manager container

    Owned by a business email address that cannot be revoked by the outgoing agency.

    03

    Merchant Center + CSS

    Confirm CSS ownership. Losing your CSS domain costs you the 20% bidding advantage overnight.

    04

    Conversion tag inventory

    Every tag, every trigger, every enhanced conversion mapping — documented before anything is edited.

    05

    Offline conversion feeds

    CRM syncs, GCLID capture, revenue-adjusted imports. These break silently and take weeks to notice.

    06

    Historical exports

    24 months at campaign, ad group, product and search term level. Stored outside the platform.

    07

    Feed rules + supplemental feeds

    Merchant Center rules and supplemental feeds rarely get documented. Extract them before access changes.

    08

    Scripts + automation

    Any Google Ads scripts, n-gram tools or bid automation currently running — with their triggers and thresholds.

    Five ways this goes wrong

    The failure modes we see in almost every rushed switch.

    None of these are theoretical. Each of them has cost a real brand a real quarter. If any of them are happening to you right now, stop and stabilise before you go any further.

    The dual-tag disaster

    Old and new conversion tags fire simultaneously. Every conversion double-counts. Smart bidding thinks performance has doubled, bids up aggressively, spend explodes, and the numbers look brilliant for exactly as long as it takes finance to notice.

    The learning phase reset

    New agency swaps bid strategies on day one because 'target ROAS is holding the account back'. The account enters learning. Revenue drops 15–30% for two to three weeks. The new agency blames seasonality. You blame the switch. Both are wrong.

    The PMax rebuild before context

    PMax gets rebuilt in week two, before anyone has opened the cost file. The new structure looks tidier and performs worse, because the previous asset groups were quietly doing commercial work nobody documented.

    The lost CSS partner

    The outgoing agency was the CSS partner. Nobody flags it. The domain lapses, Shopping bids revert to standard rates, and a 20% cost advantage disappears in a single billing cycle.

    The silent offline conversion break

    CRM-to-Google conversion imports quietly fail during the access swap. Smart bidding loses its highest-quality signal. Performance degrades gradually over 30–60 days. By the time anyone notices, the damage is compounding.

    The 90-day review

    The 90-day review is the moment a switch is judged. Get the agenda right and you protect the decision. Get it wrong and you'll spend the next quarter defending it.

    Open with contribution margin — not ROAS.

    Open with new-customer economics — not blended revenue.

    Open with the SKUs that stopped losing money — not the campaigns that grew.

    If the new agency can't lead that conversation, you haven't switched. You've re-hired.

    If you're mid-switch or thirty days out

    We'll pressure-test the transition before you break anything.

    Send us your cost file and read-only account access. We'll come back with a commercial read on what's actually inside the account, where the transition risks sit, and what the first ninety days should protect. No pitch deck. Capped at four audits a month.

    Request the audit

    What you get

    A written transition read: data ownership status, tracking continuity risks, and the profit leaks that will follow you from the current account into the new one.

    What we ask for

    A cost file. Read-only access to the ad account. Thirty minutes of your time.

    What we don't do

    Sales calls disguised as audits. If we can't help, we'll tell you and point you somewhere that can.