How to choose a B2B agency e-commerce? 10 questions worth asking

Choosing a B2B e-commerce platform is often the first decision made by companies planning to digitize B2B sales. But choosing an implementation agency—a partner who will design, build, integrate with the ERP, and maintain the platform for years to come—is equally, and often more, important. A bad platform with a good agency can be fixed. A good platform with an agency that doesn't understand the specifics of B2B sales is a recipe for a project that technically "works" but doesn't solve any real business problem.

These 10 questions are a tool for evaluating a potential vendor. These aren't technical questions—they're questions that reveal whether the agency truly understands what you need, whether they approach implementation as a partnership, and whether they're worth building a long-term digital sales business with.

Question 1: Will we be fully independent after implementation?

This question reveals one of the biggest risks in B2B e-commerce projects : vendor lock-in. This refers to a situation where, after implementation, you're effectively tied to a single vendor – because only they know the system architecture, only they have access to the code, or the technology license is tied exclusively to them.

Ask directly: If you decide to move to another provider in three years, can you do so without losing access to the system? Will you receive full technical documentation? Is the code written in open technology that many developers in the market are familiar with?

A good agency will answer these questions without hesitation. An agency that has built its business model on client dependence will navigate this. When choosing technology, it's also worth checking the licensing issue: does its cost increase with turnover or the number of orders, or is it constant regardless of scale? This is crucial in rapidly growing e-commerce . We write more about how technology choice affects independence in our article on B2B open source vs. SaaS platforms.

Question 2: What does your pre-contract signing process look like?

This question quickly reveals whether you're dealing with a partner or a vendor. An agency that sends a quote after two emails doesn't understand your business. Or it doesn't want to.

B2B e-commerce implementation is a project that interferes with sales processes, customer service, pricing, and logistics. An agency that doesn't ask questions about your current processes, pricing models, key account management, and plans for the next three years is simply pricing the project blindly. And such pricing doesn't work.

A good implementation partner starts with a diagnosis. They ask how your sales are performing today, what's hurting you most, and where you see growth. Only then do they recommend the technology and scope of implementation. This is a consulting-first approach—and it's more valuable than a simple product presentation.

Question 3: What projects do you have that are similar to our industry and scale?

B2B e-commerce isn't B2C e-commerce with a disabled "buy now" button. It has a different pricing model (contract pricing, customer discounts, payment terms), a different ordering process (recurring orders, quick quantity changes, integration with the customer's ERP), and a different service (account manager, credit limit, order history).

An agency that only implements B2C stores can technically "do B2B," but they won't know where the real pitfalls are. Ask about specific projects: what industries, what catalog scales, what integrations with ERP systems. Ask for contact information for references—and actually call them. Also, check if the agency has experience implementing B2B systems , not just B2C e-commerce .

If your industry has specific requirements – e.g., complex product configurators, service order processing, integration with a technical catalog – ask directly if the agency has had a similar project and how they handled it.

Question 4: How do you manage the project and what will our communication look like?

B2B e-commerce implementations typically last from a few to a dozen months. During this time, you need to know what's happening: who's responsible for decisions, how you report changes to requirements, and what happens if something doesn't go according to schedule.

Ask: who will be your main point of contact? What is your access to the project manager? How often are status meetings held? What tool is used to manage the task, and do you have access to it? How does the agency respond to changes in requirements – is this a standard process, or is each change a separate negotiation?

The most common reason for failed implementations isn't the technology. It's communication and managing expectations. An agency that has clear project processes and isn't afraid to discuss problems directly is a partner with whom the project has a chance of success.

Question 5: What is covered by warranty and what is not?

This question reveals the agency's willingness to take responsibility for its work. A good warranty should cover the correct operation of delivered functionalities according to the approved specifications. It should also specify the response and recovery time for critical errors.

Equally important is what the warranty doesn't cover: changes made by your team, updates to external systems (e.g., payment APIs, ERP), and modifications made by another agency. Transparency in this regard is a sign of professionalism. An agency that avoids this question or gives a vague answer, "we guarantee quality," lacks a specific policy.

Question 6: How is testing done before each production release?

In e-commerce, a production error costs money: lost orders, lower prices due to a configurator error, and ERP integration issues with a key customer order. Ask about the QA process: are new features tested manually, are there automated tests, and what processes are involved, and how platform updates are tested.

A key additional question: do you have access to a staging environment where you can test changes before deploying them to production? If the answer is "no," that's a serious red flag. Every change should go through staging and client approval before going live.

Question 7: How long will the implementation realistically take and what might extend the schedule?

Implementation time is a topic agencies tend to be optimistic about. It's not just how many weeks it will take to launch that matters, but also what's included and what's outside of that timeline.

Ask about the entire timeline: from requirements gathering, through UX design, development, ERP integration, testing, and production deployment. Also, ask what most often causes delays in similar projects—delayed client data, changes in requirements, issues with external systems? An agency that can honestly answer this question has already completed several projects where something went wrong.

Another good tip is to check benchmark implementation times for similar projects. For simpler B2B implementations – for example, on the Sellina platform – the timeline can be as little as four weeks. For a complex project with custom integrations, it can take several months. If an agency promises full implementation in six weeks without specifying a detailed scope, it's a sign that it needs to be reconsidered.

Question 8: What is the total cost of ownership of the system over a 3-year period?

The startup cost is just one line item in the overall bill. TCO (Total Cost of Ownership) also includes: the cost of the platform license (and whether it increases with revenue), the cost of hosting and infrastructure, the cost of updates (especially for open source platforms, where a major upgrade is often a separate project), the cost of new features and system changes, and the cost of technical support and maintenance.

An agency that can't or won't provide a three-year TCO estimate either lacks experience in long-term collaboration or is hiding something in its pricing model. You can also find detailed cost questions in our list of requirements for a B2B e-commerce system provider.

When comparing offers, pay particular attention to whether the platform's license is fixed or variable. A license based on turnover or order volume may seem attractive at the start, but with the growth of B2B e-commerce, it becomes a significant hidden cost. It's worth checking how individual platforms compare in this regard – you can find a detailed breakdown in the B2B systems ranking.

Question 9: What technology are you working with and what does this mean for us long term?

The technology chosen by the agency will be with you for a long time. Therefore, it's important not only whether it's relevant today, but also: how large is the developer community familiar with it? How active is the open source project? How long has the manufacturer declared support for the current version?

Practical questions: how many specialists familiar with this technology are there in the job market? If you decide to build your own team or change agencies, how easy will it be to find programmers? What is the developer community's opinion on this technology – is it being developed and valued, or is it being replaced by newer solutions?

An agency that can answer these questions concretely and without defensiveness demonstrates that it is thinking long-term. That's a good sign.

Question 10: What does post-implementation support look like – SLA and incident response?

Implementation is just the beginning. Your B2B e-commerce system operates 24/7 and serves your company's real customers. A critical error at 8 a.m. on Monday, when your B2B customers are placing weekly orders, costs money—and not just your image.

Ask about specific SLA parameters: what is the declared response time for critical errors (e.g., system unavailable, orders not being processed) and for standard errors? What is the incident reporting process like? Is there a dedicated contact channel for urgent matters, or is ticketing the only way?

A good agency has clearly defined SLA levels and isn't afraid to include them in the contract. If the answer to the SLA question is "we operate flexibly and strive to respond quickly," then there are no guarantees. For a company moving B2B sales online, this isn't enough.

Summary

Choosing a B2B e-commerce agency is a decision that will have consequences for at least several years. These 10 questions don't guarantee a perfect choice, but they do help eliminate vendors who aren't ready for a long-term partnership.

A good agency will answer each of these questions precisely, without beating around the bush or avoiding difficult topics. If at any stage of the conversation the provider becomes evasive, treat it as information, not a coincidence. If you're looking for an agency that starts by understanding your business and selects the right technology to support the diagnosis, schedule a free consultation . We'll show you our answers to each of these questions.