Migrating to Shopify Plus: Timeline, Costs and a Practical Checklist

"Migration" means two very different projects depending on where you are starting from, and conflating them is where most cost and timeline estimates go wrong. Upgrading from standard Shopify to Plus is mostly an account-level change with some checkout rebuild work. Replatforming from Magento, BigCommerce, or a custom system to Shopify Plus is a full data migration and rebuild. This post treats them separately, because they deserve separate budgets.

Scenario One: Upgrading From Standard Shopify

If you are already on Shopify (Basic, Grow, or Advanced) and moving to Plus, your product catalog, customer data, and order history stay in the same underlying system. Shopify does not require you to migrate data in the traditional sense, since you are not leaving the platform.

What actually needs work:

• Account and plan transition. Shopify's team handles the contract change and platform-level upgrade. This part is administrative, not technical.
• Rebuilding Scripts as Functions. If your store used Shopify Scripts for checkout customization (discount logic, shipping rules, payment restrictions), those do not carry over automatically. Scripts were deprecated, and equivalent logic has to be rebuilt using Shopify Functions, which is a genuine development task, not a settings change.
• Theme and app compatibility review. Most themes and apps work identically on Plus, but checkout-related apps in particular need review since Plus checkout works differently from standard checkout in some configurations.
• Enabling and configuring new features. B2B, Launchpad, expansion stores, and higher API limits are available but inactive until configured for your specific use case.

Realistic timeline: two to five weeks for most stores, depending on how much checkout customization existed pre-upgrade and how many new Plus features you want live at launch, versus rolled out gradually afterward.

Realistic cost range: $3,000 to $15,000 in development and QA work on top of the Plus platform fee itself, for a store with moderate customization needs. A store with minimal custom checkout logic and no immediate B2B needs can come in lower; a store rebuilding several complex Scripts as Functions and launching B2B simultaneously will land toward the higher end or beyond.

Scenario Two: Replatforming From Magento, BigCommerce, or Custom

This is the real project, and it deserves to be scoped like one. You are moving an entire commerce operation to a new platform, which touches data, design, integrations, and SEO simultaneously.

Phase 1: Discovery and Scoping (Weeks 1 to 2)

Audit the existing store: product catalog size and complexity, customer database, order history requirements, active integrations (ERP, CRM, fulfillment, marketing tools), and current app or extension dependencies. This phase should produce a written scope, not a verbal estimate, because migration cost varies enormously with catalog complexity and integration count.

Phase 2: Data Migration Planning (Weeks 2 to 4, overlapping with Phase 1)

• Products: variants, images, metafields, and custom attributes need mapping between the old platform's data model and Shopify's. Magento's flexible attribute system in particular often requires custom mapping logic rather than a simple export and import.
• Customers: account data, saved addresses, and (where technically and legally possible) password migration. Full password migration is not always feasible depending on the source platform's hashing method, which means planning for a password reset flow for at least some customers.
• Order history: Shopify can import historical orders, but very large histories (hundreds of thousands of orders) sometimes get summarized or archived separately rather than fully imported, depending on tooling and budget. Decide upfront what level of historical detail customers and staff actually need accessible in the new admin.
• SEO redirects: every indexed URL from the old platform needs a mapped redirect to its Shopify equivalent. This is one of the most commonly underscoped parts of a migration, and skipping it is the single biggest cause of post-launch traffic loss.

Phase 3: Checkout and Storefront Rebuild (Weeks 4 to 9)

Theme development, checkout customization through Functions, and any B2B configuration happen here. This phase runs in parallel with data migration work where possible to compress the overall timeline. If your current store relies on custom functionality unique to Magento or BigCommerce (custom pricing rules, specific tax logic, unusual shipping calculations), expect this phase to take longer, since equivalent logic needs to be rebuilt natively for Shopify rather than copied over.

Phase 4: App Audit and Replacement (Weeks 5 to 8, overlapping)

Every app or extension on the old platform needs a Shopify equivalent evaluated, whether that is a native Plus feature, a Shopify App Store app, or custom development. Common categories: reviews, loyalty, subscriptions, search and filtering, tax calculation, and shipping rate shopping. Do not assume a one-to-one app mapping exists for every extension; some functionality needs custom build work through Shopify app development instead.

Phase 5: Testing (Weeks 8 to 10)

Full checkout testing across payment methods, shipping scenarios, tax jurisdictions, and (if applicable) B2B account logic. Load testing if you have meaningful traffic volume, since undiscovered performance issues under real launch traffic are expensive to fix after the fact. QA the SEO redirect map specifically, checking a meaningful sample of old URLs rather than assuming the bulk redirect rule covers every edge case.

Phase 6: Launch and Post-Launch Monitoring (Week 10 to 12)

DNS cutover, final data sync, and close monitoring of search rankings, checkout conversion, and error logs for the first two to four weeks post-launch. Budget time here, not just for launch day. Ranking recovery after a domain or URL structure change typically takes several weeks even with a clean redirect map, and monitoring catches problems before they compound.

Cost Ranges by Scenario

Scenario	Typical Timeline	Typical Cost Range
Standard Shopify to Plus upgrade	2 to 5 weeks	$3,000 to $15,000
Small replatform (under 500 SKUs, few integrations)	8 to 10 weeks	$20,000 to $45,000
Mid-size replatform (500 to 5,000 SKUs, several integrations)	10 to 14 weeks	$45,000 to $90,000
Complex replatform (large catalog, custom B2B, ERP integration)	14 to 20+ weeks	$90,000 to $200,000+

These ranges assume a development partner handling the technical work end to end. They exclude the Shopify Plus platform fee itself, which is separate and ongoing. Every one of our case studies for replatforming projects falls somewhere on this spread depending on catalog size and integration count, and we scope each one individually rather than quoting off a generic package.

Pre-Migration Checklist

Before signing a contract with any development partner, confirm you have:

1. A full export of your current product catalog, including variants, images, and metafields, not just a live admin login.
2. A complete list of every third-party integration currently connected: ERP, CRM, email platform, tax software, fulfillment, subscription billing.
3. Google Search Console access and a current sitemap, needed to build an accurate redirect map.
4. A decision on order history depth you need accessible in Shopify versus archived elsewhere.
5. A defined B2B requirement, if applicable, documented in enough detail (pricing tiers, payment terms, account structures) that a developer can scope it accurately.
6. A realistic launch date that avoids your peak sales period. Never launch a replatform in the six weeks before your biggest revenue month.
7. A rollback plan agreed with your development partner in case launch reveals a blocking issue.

Mistakes That Cause Traffic Loss

The migrations that hurt SEO and revenue almost always share the same root causes:

• Incomplete redirect maps. Redirecting only top-level category pages while missing deep product and blog URLs leaves a large share of indexed pages returning errors, which search engines penalize quickly.
• Launching during peak season. Any platform change carries risk of unexpected issues in the first days. Launching two weeks before a major sales event turns a manageable bug into a revenue crisis.
• Skipping load testing. A store that performed fine on the old platform can behave differently under Shopify's infrastructure and checkout flow, particularly with custom Functions added. Test under realistic concurrent traffic, not just single-user QA.
• Losing structured data and metadata. Product schema markup, meta descriptions, and alt text sometimes get dropped in a rushed migration because they are not considered part of "the data" the way price and inventory are.
• Underestimating password migration friction. Forcing every customer to reset their password without clear communication increases support tickets and can suppress repeat purchase rates in the weeks after launch.

Every one of these is avoidable with a documented plan rather than an ad hoc migration. If your team is also considering broader platform work, our ecommerce development services cover the surrounding pieces (integrations, custom features) that often get bundled into a replatform project.

FAQ

How long does a full Magento to Shopify Plus migration usually take?

For a mid-size catalog with several integrations, plan on 10 to 14 weeks from discovery to launch. Larger catalogs, custom B2B requirements, or ERP-dependent workflows extend that to 14 to 20 weeks or more. Rushed timelines under eight weeks for a complex replatform usually mean corners get cut on testing or redirects.

Will we lose our search rankings during the migration?

Some temporary fluctuation is normal even with a clean migration, since search engines need time to recrawl and re-index the new URL structure. A complete, accurate redirect map keeps this fluctuation minor and temporary rather than a lasting loss. Incomplete redirects are the main cause of permanent ranking damage.

Can we migrate order history and customer accounts together, or does it have to be phased?

Both can typically move together, but customer password migration depends on the old platform's password hashing method. Some platforms allow direct migration; others require customers to reset their password on first login. Confirm this early since it affects your launch communication plan.

Do we need to replace all our current apps when moving to Shopify Plus?

Not all of them. Some have direct Shopify equivalents in the App Store, some functionality becomes native (particularly around B2B and checkout), and a smaller number need custom development to replicate. A proper app audit during discovery identifies which bucket each one falls into before the build phase starts.

If you are weighing a Shopify Plus migration and want an honest scope and cost estimate for your specific catalog and integrations, rather than a generic quote, we walk through it in detail as part of our Shopify Plus migration work. Book a free 1-hour strategy call through our contact page and bring your current platform details.