Seller Onboarding: How to Manage Supply for Marketplaces

The first step for any marketplace transaction is that sellers need to make whatever they’re selling available to buyers. This may be products, services, assets to rent or share, or themselves. Sellers will need a place on the platform where they can manage their profile and availability of their offerings. This is often done through a seller dashboard that includes the ability to edit their information, add products or services, and see their transaction history. There are many things to consider in building supply for marketplaces, which we outline below.

How does the seller create their profile? 

In most marketplaces, sellers will have some sort of public profile that buyers can use to build trust. Sometimes this is the focus of the entire seller offering, like in the case of freelancer profiles on a gig marketplace like Upwork or Fiverr. Other times it is secondary to the items they are offering, like in the cases where the physical product or asset on the marketplace is the main focus. Once again, you should err on the side of only collecting or requiring information that you think is necessary for the buyer to feel comfortable in the transaction. This generally means collect basic info such as name, email, phone number, zip code, and maybe a profile image and bio. There are different ways to collect this information and get a user set up. 

Example Profile Page
This is a sample UI from our Canvas modular no-code design framework

Simple user account

Marketplaces that focus on the product over who is selling it may not need a robust seller profile, and you can keep things simple. In these cases, you may just want to ask for a name, email, and location if they are shipping things.

Create from scratch

If your marketplace requires unique information from each seller that they wouldn’t have entered somewhere else, such as a custom bio or description of assets, creating an onboarding flow where users enter the information in a step-by-step way can make things easy and streamlined.

Pull in third-party information

Sometimes you can use social authentication to pull in relevant information such as through a user’s LinkedIn or Facebook account. This makes it very easy on sellers, though you may want to offer options for them to enter the information manually as well. You can also allow users to link to other sites such as their personal website if there is too much dropoff when asking them to create a new profile on your platform.

Claim existing profile

In some cases, you can generate a list of profiles and have users claim theirs. This works well in cases like Yelp or with properties where you can integrate with a tool that pulls all the relevant information from an address. You can also explore using scraping tools to pull in information and create profiles that you send to potential users to claim.

What is being offered?

Whether offering products or services, an important distinction is how complex or layered the seller’s items are. This determines the complexity of the database structure and the user experience in both managing items and choosing them as a buyer, so it is important to recognize the potential cost and timing implications if you are doing a custom build. Below are three typical options for offering complexity.

Seller’s time

When a seller is offering their services, they are the product being offered. If their work is fairly customized per buyer, then all you need to display is their profile, and the buyer and seller can discuss specific terms as part of the transaction. This is the simplest option because once the seller completes their profile, they are done.

Single-layer items

This is the most common option, where sellers have a list of items they are offering. This can be anything from physical products to assets, or even specific service offerings. This type includes things like renting a car like Turo, selling a unique piece of art, or offering a specific service like a $5 logo design. Each product is unique and has only one version.

Example Asset Rental Product Page
This is a sample UI from our Canvas modular no-code design framework

Item variants

This is a common ecommerce experience, where each item for sale can have different versions nested underneath. These are things like different clothing sizes, different colors, or different lengths of time. Nesting these variants can make it easier for sellers to manage and easier for buyers to find what they want. It does introduce a new layer of complexity to both the data structure and user interface for browsing, which can be costly to set up. However, it may be worth it depending on how many variants of each offering the seller has.

Example Product Page with Variants
This is a sample UI from our Canvas modular no-code design framework

How to manage quantity?

Managing the inventory numbers for items on your marketplace is another factor to consider when building the product. It’s important to ensure the quantities of items are accurately displayed to the buyers and easy to manage for the sellers. There are a few different options here.


In some cases, we can assume the quantity of each item offered is 1, and once it’s sold, it’s gone from the platform. This is common for collectors items (e.g., comics) and secondhand or used marketplaces. This simplifies the complexity of the build and makes it easy for sellers to manage inventory since they don’t have to restock quantities in the platform.

Replenishable inventory

This is most common for standard product marketplaces, where sellers manage an inventory level for each item or variant. For example, a seller may have 100 candles, and if someone buys 12, they have 88 left. They could make more and add to their inventory to increase the numbers. For these cases, you will need an interface for buyers to select a quantity to purchase, logic to reduce the inventory numbers upon purchase, and a place where sellers can update inventory if they add more.


Some offerings, particularly in event-based or space-reserving marketplaces, have capacity limits. This is when each item or event has a capacity level that is not necessarily replenished. For this you would need a place for the seller to input a capacity number and logic to reduce that number as people book or reserve.


Some items are made-to-order by the seller upon purchase. This is a technically easy option because the seller doesn’t need to manage inventory, the buyer can choose any quantity, and the item simply stays up for sale since the seller makes the item each time it is ordered. This is common for crafts and food.

How to manage availability?

Service and rental marketplaces often require timing coordination as part of the transaction, such as scheduling an appointment or booking a stay. Usually the first part of this process is for the seller to indicate when the item is available, so prospective buyers know and can filter for their preferences. There are a few options for how to handle this.


The first is to just allow the seller to write their availability as text (e.g., “weekdays 9-5”). This is technically simplest and most flexible since they can write it however they want, but it doesn’t represent real data that can be matched against, so it only works if buyers are reading and understanding it, and requesting services manually. This may be a good place to start as you’re building and validating your MVP.


Another option is for sellers to offer explicit timeslots someone can book. This is still technically pretty simple because each slot is at a fixed time and has two states: open or booked by someone. However, it can be a bit restrictive or cumbersome for sellers since they need to choose each explicit start and end time versus choosing a window that someone can book anytime within. If you go this route, you may want to offer the ability to setup recurring times or duplicate times.

General Availability

A more flexible approach is to allow the seller to create explicit ranges for their availability such as each weekday 9-5pm, with options for blackouts or unavailable dates such as holidays. This option is more flexible than explicit timeslots because a buyer can book anytime within an available span. When one buyer books a time, it becomes a new unavailable span to prevent double-booking. You can explore integrations such as Calendly to reduce development time and improve the seller experience, however, this can come with some tradeoffs such as not being able to see when the bookings are on the platform and connect payments directly to the booking process. You can also create an integration directly with the seller’s calendar. This would require some technical work to integrate directly with Google or Outlook, though you can use a tool like Nylas to help with the integrations.

Live on-demand

Sometimes services are booked in real-time instead of scheduled, like in the case of ride-sharing or food delivery. In this case, the seller can just indicate in real time whether they are available or not, and buyers will get matched or be able to search for available sellers.

Who posts and manages items for sellers?

It’s common for sellers to manage their offerings themselves, but in some cases it makes sense for the marketplace to have more control. This can be useful early on as you are building and learning from your users. It’s a balance of security versus speed and ease of use, and should only be used if it’s essential for maintaining trust and quality.

Sellers have full control

This is most scalable and easiest for growth since it’s completely decentralized, and it gives your sellers the best experience. This is encouraged if you’ve already pre-vetted seller profiles and if they’re professionals (vs. amateurs), since the quality will be better. It does take more up-front development effort since you need to create the seller interface to allow them to manage all their information.

Admins manage centrally

This is a good option early on when scale is low and you want more quality control. You can collect items as part of seller onboarding or even manually and setup their products or inventory yourself. This would be a simple initial build and you can accept payments and then distribute them offline.

Admins approve

This is a hybrid approach where sellers post items and an admin approves the posts to go live. You may implement this when you want to provide feedback to sellers on their posts, such as to encourage better photos or descriptions, before allowing them to go live.

How is pricing set?

Pricing is an important factor for your marketplace, and will be critical in determining the success of your marketplace. If items are priced too high, buyers will not want them. However, if prices are too low, sellers will not be motivated. Determining how to price items or how to encourage pricing ranges by sellers can be done in different ways.

Fixed price

This is where the seller sets a single price for an item (or variant) that is fixed. Buyers can choose to purchase the item or service at that price and directly make a transaction. It is simple to set up and manage, and a common strategy for product or asset marketplaces.

Suggested price

If there is potential for negotiation or back and forth, sellers can set a suggested price. This could be an expected hourly rate or estimate for different types of services. In this case, you’ll want to allow for a negotiation of terms, with the price getting finalized at the point of the transaction.


If your marketplace is set up like an auction site similar to eBay, the seller may set a starting price, bid increments, and a reserve price (the minimum price the auction must hit). For this, you’ll also want to consider the auction time window and how to notify buyers when they’ve been outbid.

Platform-set pricing

Sometimes the platform itself will set the price. For fixed prices, you can create standards for how to price certain items and then automatically attach them to the product or service. Prices can also be set dynamically, like in the case of Uber determining ride prices based on demand and driver supply. This requires creating a system or algorithm to calculate the appropriate price based on a variety of factors.

Promos and sales

Sometimes sellers will want the ability to provide promotional codes on their items such as a percentage or fixed dollar amount discount on some or all items.

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