Two agencies can quote the same B2B replatform and land three times apart. Usually that is not one of them overcharging. It is that they scoped different projects, because the buyer's requirements were never pinned down well enough for the quotes to be comparable.
This is the scope we actually work from, phase by phase, with what makes each one cheap and what makes it expensive. It is written so you can find your own project in it before you talk to anyone.
TL;DR: Every B2B project is different, so there is no meaningful price per phase. What there is, is a consistent set of things that make a project simple or complicated. Almost all of them are requirements you already have, whether or not they are written down.
The Phases
Discovery & Planning
Requirements workshops with sales, finance and operations, technical architecture, the data contract between systems, and information architecture.
Straightforward when: Requirements are documented, one decision-maker, existing process is understood.
Gets complicated when: Nobody can describe how pricing actually works today, three departments disagree, or the current process lives in one person's head.
UX & Design
Wireframes, high-fidelity design, and a formal review and approval gate.
Straightforward when: You accept a proven B2B layout and have a brand guide.
Gets complicated when: Every screen is bespoke, approval needs a committee, or design restarts after development begins.
Shopify Plus Store Setup
Store provisioning, environments, platform configuration, shipping and tax setup.
Straightforward when: One region, standard shipping, straightforward tax.
Gets complicated when: Multiple regions, freight or LTL shipping, per-customer shipping rules, or complex tax nexus.
Theme Development
The custom theme base and global components, homepage, category and landing pages, product detail and listing pages, resource or document libraries, blog templates, forms and utility pages.
Straightforward when: You use a themed base and accept standard templates.
Gets complicated when: Every template is custom, you need a document or spec-sheet library, or product pages must render technical data that varies by product type.
B2B Functionality
Companies, locations and contacts, registration with credit application and approval, rep or agent portals, quick order and bulk upload, RFQ and order workflows, product comparison.
Straightforward when: Native Shopify B2B covers your model: companies, catalogs, payment terms, self-service ordering.
Gets complicated when: You need sales-rep hierarchies, agent-controlled pricing within floor and ceiling limits, multi-stage internal approvals, or quoting that native B2B does not do. This is where custom development concentrates.
Product Data Architecture
Product structure and metafield schema, catalog import, legacy SKU handling.
Straightforward when: Clean catalog, consistent attributes, a manageable SKU count.
Gets complicated when: Tens of thousands of SKUs, inconsistent historical data, technical specifications that must stay filterable, or legacy SKU formats that customers still order by.
Search
Native Shopify search and discovery configuration, or a third-party search platform.
Straightforward when: Native search handles your catalog.
Gets complicated when: Buyers search by part number, cross-reference or specification, which usually means a dedicated search platform.
Content & Copy
Content placement and formatting, utility and about pages, blog migration, form and system messaging.
Straightforward when: Content exists and transfers largely as-is.
Gets complicated when: Content needs rewriting, or a large blog or resource library has to migrate with its URLs intact.
Email & Notifications
Transactional email templates and email service provider integration.
Straightforward when: Standard templates, one ESP.
Gets complicated when: Different notifications per customer type, or transactional email that has to reflect account-specific terms.
Analytics & Tracking
GA4, search console verification, A/B testing setup, behavioural analytics, server-side tracking.
Straightforward when: Standard GA4 and a tag manager.
Gets complicated when: Server-side tracking, multiple destinations, or B2B-specific event models that off-the-shelf setups do not cover.
SEO
URL mapping and 301 redirects, schema markup, meta management.
Straightforward when: Small site, simple URL structure.
Gets complicated when: Thousands of indexed URLs, legacy path structures, or parameters that multiplied your indexed pages. Our migration SEO guide covers what this involves.
Accessibility & Compliance
Accessibility standards in the build, cookie, privacy and consent compliance.
Straightforward when: Built in from the start.
Gets complicated when: Retrofitted after launch, or you are subject to a specific compliance standard or an existing complaint.
Testing & QA
Cross-browser and device testing, performance and accessibility audits, B2B role and flow testing, user acceptance testing and bug fixes.
Straightforward when: Few customer types, simple pricing.
Gets complicated when: Many customer groups with different catalogs, prices and terms. Every combination is a test case, and this is the phase most often underestimated.
Launch & Handoff
Launch execution, training sessions, documentation, source code and technical handoff.
Straightforward when: One team, one training session, straightforward cutover.
Gets complicated when: Phased rollout by customer segment, multiple teams to train, or a cutover that has to avoid a busy season.
Post-Launch Support
A defined window of included support after go-live.
Straightforward when: Standard included window.
Gets complicated when: Extended hypercare, or a launch where a long tail of customer-specific issues is expected.
Project Management
Project management, status meetings, PM tooling and the code repository.
Straightforward when: Fast decisions, one stakeholder.
Gets complicated when: Many stakeholders, slow approvals, or a long timeline. PM scales with elapsed time, not with build complexity, so a project that drags costs more in PM even if nothing else changes.
Optional Add-Ons
Middleware and integration ownership, premium search, and similar.
Straightforward when: Not needed, or you own the middleware.
Gets complicated when: You want the agency to own the integration layer long-term rather than hand it back.
The Five Things That Decide How Big a Project This Is
- How far your B2B model is from native Shopify. Companies, catalogs, payment terms and self-service ordering are built in. Rep hierarchies, agent-controlled pricing and multi-stage approvals are not. The distance between those two is the single biggest variable in the project.
- Catalog size and data quality. Not just SKU count. Whether attributes are consistent, whether specifications need to stay filterable, and whether customers still order by legacy part numbers.
- How many customer types you have. Each combination of catalog, price list and payment terms is a test case. Testing effort grows with combinations, not with customers.
- Whether the ERP owns pricing. If prices live in the ERP and must be right in real time, that is an integration problem rather than a commerce configuration problem, and it is priced accordingly.
- How fast you can make decisions. Project management scales with elapsed time. A project that takes twice as long costs more in PM even if the build is identical.
What You Pay That Is Not the Build
These are ongoing costs to you, not agency fees, and they are easy to leave out of a budget:
- The Shopify Plus plan. See our Shopify Plus cost breakdown.
- Your ERP and its licensing.
- Middleware or integration platform fees, if you use one.
- Search platform, if native search will not do.
- Email service provider.
- Analytics and tracking add-ons, particularly server-side tracking.
Questions to Ask Any Agency Quoting You
If you are comparing proposals, these separate a scoped quote from a guess:
- Which of my B2B requirements are native Shopify, which are apps, and which are custom development?
- What is your assumption about my catalog data quality, and what happens to the price if it is worse than that?
- How many customer-type and price-list combinations have you scoped for testing?
- Which system owns pricing in your design, and what happens when it is unavailable at checkout?
- What is in the fixed fee, and what is explicitly out?
- What are the third-party costs I will pay directly, on top of your fee?
A quote that cannot answer these is not a quote, it is an estimate wearing a quote's clothing. Our B2B implementation guide covers the requirements work that makes these answerable.
Scoping a B2B Replatform?
Bring us your customer types, your pricing rules and your systems list, and we will tell you which parts of this scope your project actually needs. Explore our Shopify B2B development services or talk to us directly.
Frequently Asked Questions
How much does a Shopify B2B replatform cost?
It depends almost entirely on how far your B2B model sits from native Shopify functionality, your catalog size and data quality, and how many customer-type and pricing combinations exist. Those three drive most of the variance. Rather than quote a range that would not survive contact with your requirements, this guide sets out the full scope so you can identify which parts your project needs before asking anyone for a number.
Which part of a B2B replatform is hardest to predict?
B2B functionality, because it is where custom development concentrates. Native Shopify covers companies, catalogs, payment terms and self-service ordering. Anything beyond that, such as rep hierarchies, agent-controlled pricing or multi-stage approvals, is built rather than configured, and how much of it you need varies enormously between businesses.
What makes a B2B project expensive?
Sales-rep hierarchies, agent-controlled pricing with floor and ceiling limits, multi-stage internal approval workflows, large or inconsistent catalogs, many customer groups with different catalogs and terms, and an ERP that owns pricing in real time. Any one of these moves a project meaningfully; several together change its category.
What is not included in an agency's fee?
Typically the Shopify Plus plan, your ERP licensing, middleware or integration platform fees, a search platform if you need one, your email service provider, and analytics add-ons such as server-side tracking. Ask for these to be listed explicitly, since they are ongoing costs you pay directly.
How long does a Shopify B2B replatform take?
It depends on the same drivers as cost, plus how quickly your team can make decisions and approve work. Project management scales with elapsed time rather than build complexity, so slow decision-making makes a project more expensive as well as longer. Estimate after discovery, with separate milestones for configuration, data migration, integration validation and business acceptance testing.
Do I need Shopify Plus for B2B?
Not necessarily. Core B2B features are available on all Shopify plans. Plus adds unlimited catalogs, direct catalog assignment to companies and locations, deposits and partial payments, checkout customization, and expansion stores. Our Shopify Plus cost breakdown covers when the upgrade pays for itself.