May 1, 2026

Shopify Plus Migration: The Complete Guide for $5M-$100M Brands

Migrating to Shopify Plus from Magento, BigCommerce, WooCommerce, Salesforce CC, or a custom build. Timeline, cost, SEO and what actually breaks.
7 min read
Flux Insights Static HeroAdam, Fractional CEO, smiling man with short dark hair and beard wearing a black shirt in a bright office environment
Adam Tregear
Founder @ Flux
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Most Shopify Plus migrations don't fail at the platform decision. They fail at the redirect map, the data reconciliation, or the cutover rehearsal that nobody scheduled. The platform is the easy part.

This is the playbook we use across every migration we run. It's platform-agnostic by design because the destination is the same. The source decides the timeline and the unique problems. The destination decides the structure of the work.

Why brands move to Shopify Plus

The reasons are always some combination of cost, velocity, and capability.

Cost shows up first. Renewal quotes from Salesforce Commerce Cloud and Adobe Commerce have pushed mid-market brands toward platforms with predictable licensing. Hosting and patching on Magento and WooCommerce add operational overhead that scales with traffic. The dev rates for Magento, SAP Commerce Cloud, and custom builds are 1.5 to 3x higher than Shopify Plus rates because the talent pool is smaller and shrinking.

Velocity is the second driver. Brands on legacy platforms ship features quarterly. Brands on Shopify Plus ship weekly. The compounding effect over 12 months is significant: a year of monthly experiments versus four releases.

Capability is the third. Shopify Plus has invested heavily in checkout extensibility, B2B, Markets, and the Hydrogen headless stack. For brands that need any of those, the migration is what unlocks them.

The honest version is that no brand migrates for one reason. Cost gets the conversation started. Velocity decides who's actually ready to move. Capability tips the decision.

What "migration" actually means

Migration isn't a single workstream. It's five running in parallel.

1. Catalogue migration. Products, variants, options, images, metafields, collections, and tags get translated from the source platform's data model into Shopify's. The translation document is called a catalog mapping, and it's built before any data moves. Different platforms model products differently. Magento's EAV data model is the most complex. WooCommerce's custom post types are flexible but inconsistent. BigCommerce and Salesforce Commerce Cloud are closer to Shopify but still need mapping for option sets and custom fields.

2. Customer and order migration. Customer records, addresses, marketing consent, tags, and order history move across. Passwords don't. Every customer needs a forced password reset on first login because hashed passwords can't transfer between platforms. The detail here matters more than people expect, especially for B2B brands. See the full breakdown in customer account migration.

3. SEO preservation. Every URL on the old store needs a destination on the new one. The artifact is a 301 redirect map. For mid-market brands this is 5,000 to 50,000 URLs. We've covered the SEO playbook in detail in the hidden costs of platform migration post. Skip this step and rankings drop within 7 to 14 days.

4. Integration re-architecture. ERP, 3PL, email, reviews, subscriptions, loyalty, search. Each integration needs a connector that points at Shopify instead of the old platform. Some are app-store installs. Some are custom builds. The integration list is usually longer than the merchant remembers. We covered the operational layer in why your Shopify Plus store needs an operations strategy.

5. Design and front-end build. The new store gets designed, built, and populated. Classic Shopify Plus uses Liquid themes and the Online Store 2.0 architecture. Headless uses Hydrogen, Next.js, or a custom front-end with the Storefront API. The decision between classic and headless deserves its own conversation, covered in when should your Shopify Plus store go headless.

These five workstreams overlap, but they aren't the same. Treating them as one project is the most common reason migrations slip.

The nine paths in

Where you're coming from changes the work. Here's the short version of each.

Magento to Shopify Plus. The most common migration we run. Cost and velocity are the drivers. Data migration needs custom scripting because of the EAV data model. Most projects run 12 to 20 weeks. Read the full Magento to Shopify Plus guide.

Adobe Commerce to Shopify Plus. Same engine as Magento Commerce, different licence. Migration mechanics are identical. The conversation usually starts at renewal.

WooCommerce to Shopify Plus. The plugin stack is the issue, not WordPress. Brands hit a ceiling around $5M to $15M revenue where the plugin stack starts breaking under load. Faster migration than enterprise platforms because the data model is simpler.

BigCommerce to Shopify Plus. Brands rarely leave BigCommerce for the price. They leave for the integrations, the checkout, and the developer ecosystem.

Salesforce Commerce Cloud to Shopify Plus. The SFCC migration is rarely about capability. It's about the invoice at renewal. SFCC's revenue-share pricing breaks down at scale. Migrations from SFCC are longer and more expensive than other platforms because integration depth tends to be heavier.

SAP Commerce Cloud to Shopify Plus. The enterprise move. SAP Commerce Cloud (formerly Hybris) brands usually have deep ERP integration that needs careful redesign. Timelines stretch.

Oracle Commerce to Shopify Plus. Modernising off legacy. Oracle Commerce stores tend to have years of customisation and unsupported extensions. Migration is also a chance to retire what's no longer used.

Custom platform to Shopify Plus. The build that got you to $20M can't get you to $50M without a team you don't want to maintain. Bespoke logic gets translated into Shopify Functions, Flow, and metafield-driven workflows.

Shopify to Shopify Plus. Not a migration in the traditional sense. A capability upgrade. Same platform, more features. Different work, but the redirect map and integration repoint still apply if domains or URL structures change.

The phases of any migration

The shape of the work is the same regardless of where you're coming from.

Phase 1: Audit and planning (2 to 3 weeks). We document everything on the current platform: products, customers, orders, integrations, custom code, third-party apps, redirect history, page templates, and SEO performance. The output is the catalog mapping document, the redirect map, the integration inventory, and the build spec.

Phase 2: Data migration scripts (3 to 5 weeks). Custom scripts get written to extract data from the source, transform it against the mapping document, and load it into Shopify. The first run goes into a migration sandbox. Reconciliation passes happen weekly until product, variant, and customer counts match 1:1.

Phase 3: Build and integrations (4 to 8 weeks). The new store gets built. Integrations get connected. Apps get configured. Checkout extensions get developed. Email flows get migrated to Klaviyo or whichever ESP is in use.

Phase 4: Reconciliation and rehearsal (2 to 3 weeks). Final data delta, end-to-end QA, redirect map loaded and verified, cutover rehearsed at least twice on staging.

Phase 5: Cutover and stabilisation (1 week + 30 days). Live launch happens in a maintenance window, usually overnight or Sunday morning. The 30 days post-launch are where things break and get fixed: redirect gaps surface, integration edge cases appear, and the first round of customer support tickets reveal what didn't quite carry over.

Timeline reality

Mid-market migrations run 10 to 20 weeks. The variance comes from data complexity, integration count, and design scope.

Source platformTypical timelineWhat stretches itWooCommerce8 to 14 weeksPlugin replacement decisionsBigCommerce10 to 14 weeksCustom field mappingShopify (upgrade)6 to 10 weeksNew features being adoptedMagento / Adobe Commerce12 to 20 weeksCatalogue size, EAV complexitySalesforce Commerce Cloud14 to 22 weeksIntegration depth, custom cartridgesSAP Commerce Cloud16 to 24 weeksERP integration, B2B complexityOracle Commerce16 to 24 weeksLegacy integrations, custom codeCustom platform12 to 24 weeksBespoke logic translation

The numbers above are floor-to-ceiling for a clean scope. Brands who add scope mid-project (rare to find one that doesn't) usually finish 20 to 40% over.

Cost reality

Migration cost is driven by four things: catalogue size, integration count, design scope, and data quality.

Catalogue size matters less than people think above 1,000 SKUs. The mapping work is fixed regardless of catalogue size. The data migration scripts are the same. What scales is the QA effort.

Integration count matters more than catalogue size. Every integration is a connector to build, test, and maintain. A brand with 4 integrations migrates faster than a brand with 12. Apps from the Shopify App Store help but don't eliminate the work because most need configuration that matches your business logic.

Design scope is where projects expand or contract. Lifting-and-shifting the existing design (we don't recommend this) is faster than a redesign. Most migrations include a redesign because the existing design was a constraint of the old platform.

Data quality is the silent driver. Stores with clean product data, deduplicated customers, and current redirects move faster. Stores with 15 years of accumulated drift take longer.

We covered the line items in detail in the hidden costs of platform migration. The short version: budget the migration, and budget the 90 days post-launch separately. Both are projects.

The decisions you'll make

Five decisions shape every migration. They get made early or they get made late and expensive.

Classic Shopify Plus or headless. Classic uses Liquid themes and is faster to build. Headless uses Hydrogen or Next.js and gives you complete front-end control. For most brands under $30M revenue, classic Plus is the right call. Above $30M with international, B2B, or content-heavy needs, headless usually wins.

Search. Shopify's native search is good enough for stores under 5,000 SKUs with simple filtering needs. Above that, Algolia is the benchmark.

Content management. Liquid handles content fine for product-focused stores. Brands with editorial content, multi-region content, or rich product storytelling usually pair Shopify with Sanity or another headless CMS.

Subscriptions. Native Shopify Subscriptions, Recharge, Bold, Skio, and Yotpo are the main options. The choice affects checkout, customer portal, and revenue reporting. Worth deciding before catalogue mapping, not after.

Apps versus custom development. Most brands enter migration with 30 to 50 apps installed. Most exit with 12 to 20. Migration is the moment to audit, replace, or rebuild. Custom development costs more upfront but eliminates per-month app fees that compound.

What you should expect from a partner

A Shopify Plus migration partner does five things well.

They run a real audit before quoting. Anyone quoting a migration without seeing your data, integrations, and traffic is guessing. The audit takes 3 to 10 days and outputs a build spec, a risk register, and a fixed-price Phase 1 quote.

They write custom scripts, not CSV imports. CSV imports lose data on every migration above 5,000 SKUs. Mid-market migrations need custom scripts that understand the source platform's data model.

They reconcile data weekly. Every week of data migration ends with a reconciliation pass against the source. Counts match, attributes match, customer fields match. If reconciliation fails, the next week starts with fixing it.

They rehearse cutover at least twice. The cutover plan is a runbook, not a meeting. It gets executed end-to-end on staging twice before go-live. Anything that fails the rehearsal gets fixed before launch.

They stay engaged for 30 days post-launch. The first month is where edge cases surface. A partner who hands off at launch is a partner who hasn't done many migrations.

We've gone deeper on the partner question in what a $5M-$100M+ ecommerce brand should expect from a Shopify Plus agency.

How migrations fail

Three failure modes account for almost every bad migration.

The redirect map is the wrong size. A complete map covers every URL with organic traffic in the last 12 months. Most agency-built maps cover only the URLs in the current sitemap, which misses long-tail blog posts and old collection URLs that still rank. Rankings drop on the missed URLs. Recovery takes 6 to 18 months.

Data isn't reconciled before launch. Migrations ship with broken filters, missing variants, or inflated SKU counts because reconciliation happened once at the start, not weekly. The merchant finds out post-launch when something doesn't show up in search.

Cutover wasn't rehearsed. The cutover plan is a runbook with timed steps. If it hasn't been run end-to-end on staging, the live cutover discovers the gaps. DNS doesn't propagate, payment tokens don't transfer, redirects don't fire, integrations point at the old store. Each one is a 1 to 4 hour outage.

The good news is all three are preventable. The bad news is they only get prevented when someone treats them as core scope, not housekeeping.

Where to start

If you're planning a migration, the first step is an audit. Not a sales call. An audit.

The audit answers: how big is the catalogue, how many integrations, how clean is the data, what's the redirect surface area, and what's realistic for timeline and budget. The output is enough to make a go/no-go decision and to scope a Phase 1 build accurately.

If you'd rather start with the platform-specific guide for where you are now, jump to the migration page for your source: Magento, Adobe Commerce, WooCommerce, BigCommerce, Salesforce Commerce Cloud, SAP Commerce Cloud, Oracle Commerce, custom platform, or Shopify to Shopify Plus.

Or browse the rest of our Platform Migration insights for deeper coverage on cost, SEO, conversion impact, and the operational decisions that come with a re-platform.

Frequently asked questions

How long does a Shopify Plus migration actually take?

Most mid-market migrations run 10 to 20 weeks end-to-end, with the variance driven by source platform complexity and integration depth. WooCommerce and BigCommerce migrations typically land at 8 to 14 weeks. Magento and Adobe Commerce land at 12 to 20. SAP Commerce Cloud and Oracle Commerce can run 16 to 24 weeks because of ERP integration depth and B2B workflow complexity.

Can I migrate to Shopify Plus without losing my Google rankings?

Yes, but only if the SEO work is treated as core scope rather than housekeeping. The 301 redirect map needs to cover every URL with organic traffic from the last 12 months, not just the URLs in the current sitemap. Schema markup, canonical strategy, and sitemap submission all need explicit attention. Get those right and traffic stays flat through cutover.

Do I need a custom theme or can I use a Shopify template?

For brands above $5M revenue, a custom theme or Hydrogen headless build is almost always the right call. Templates work for early-stage stores but break down fast at mid-market scale because of bespoke merchandising, custom product types, and content depth. The migration is the right moment to invest in a build that scales with the next 5 years.

What happens to my customer passwords during migration?

Customer passwords cannot transfer between platforms because they're stored as one-way cryptographic hashes generated by different algorithms. This is true for every platform pair. The standard resolution is a forced password reset on first login post-launch, communicated through a launch-day email campaign.

What's the biggest mistake brands make on migration?

Treating migration as one project instead of five parallel workstreams. Catalogue, customer/order, SEO redirects, integrations, and front-end build all run in parallel and have different timelines. When teams collapse them into a single Gantt chart, dependencies get missed and the project slips by 4 to 8 weeks.

Should I redesign during migration or after?

Most migrations include a redesign because the existing design was a constraint of the old platform. The exception is brands actively rebranding within 6 months of migration, where it makes sense to redesign at migration time and avoid two design sprints. For everyone else, designing during migration is standard.

How much should I budget for the first year on Shopify Plus?

A typical mid-market brand running a clean migration spends $225K to $600K in year one excluding platform licence and payment processing. That covers the audit, build, post-launch retainer for 6 months, app stack, integration tooling, and internal time. Year two run rate drops to roughly $80K to $230K excluding licence as costs settle.

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TLDR Summary
  • Migration is five parallel workstreams: catalogue, customer/order, SEO redirect mapping, integration redesign, and front-end build. Treating them as one project is the most common reason migrations slip.
  • Most mid-market Shopify Plus migrations run 10 to 20 weeks. Source platform decides the variance: WooCommerce and BigCommerce land at 8-14 weeks, Magento and Adobe Commerce at 12-20, SAP and Oracle at 16-24, custom platforms at 12-24.
  • The 301 redirect map is the most under-resourced part of every migration and the single biggest cause of ranking losses post-launch. A complete map covers every URL with organic traffic in the last 12 months, not just the current sitemap.
  • Three failure modes account for almost every bad migration: incomplete redirect map, data not reconciled weekly against the source, and cutover not rehearsed end-to-end at least twice on staging before go-live.
  • The audit phase is non-negotiable. Quotes written without seeing data, integrations, and traffic are typically 30 to 50% off reality. Custom scripts beat CSV imports above 5,000 SKUs. Reconciliation runs weekly, not once at the end.
  • Most brands enter migration with 30 to 50 apps installed and exit with 12 to 20. The migration is the moment to audit, replace, or rebuild the operational stack, not just lift-and-shift the existing setup.
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