3PL vs In-House Fulfilment: A Decision Framework for Growing UK Brands

In-house fulfilment can be a practical option for brands at an earlier stage of growth. As order volumes, product ranges, and operational complexity increase, however, brands may need to reassess whether their existing fulfilment model can still support growth. In this guide, we’ll explore the differences between 3PL vs in-house fulfilment and provide a practical framework for choosing the right model for your brand.

Many eCommerce brands follow a similar path when it comes to growth. They often start small, handling fulfilment in-house with ease. As time passes and order volumes increase, warehousing, storage, staffing and returns become more complex. At this point, brands generally have two options: continue investing in their in-house team or begin outsourcing fulfilment.  

It’s important to recognise that there is no right or wrong answer for brands. Brands should make this decision based on real factors such as volume, space, technology, operational complexity and growth plans. 

There isn’t a single order volume that means you should switch to 3PL solutions. The decision usually becomes more relevant when fulfilment starts consuming management time, warehouse space, capital or operational capacity that could otherwise support growth.

Why your fulfilment matters more as you grow

Many brands think of fulfilment simply as a warehouse function, but its impact extends much further. Effective fulfilment solutions can support customer experience, delivery performance, inventory accuracy and scalability. For some brands, working with a specialist 3PL can provide access to the people, systems and infrastructure needed to maintain these standards as volumes increase.

• Customer experience: Effective fulfilment supports accurate, timely deliveries and a smooth returns process, helping brands maintain a positive customer experience.
• Delivery performance: eCommerce fulfilment services can help brands dispatch faster, improve carrier reliability and increase order accuracy.
• Cash flow: Moving to a 3PL can replace some fixed infrastructure and staffing costs with more variable fulfilment costs, depending on the provider’s pricing model. This can give brands greater cost visibility and reduce the need for upfront investment in additional warehouse space and equipment.
• Inventory control and accuracy: Reliable 3PL providers can help improve inventory accuracy through structured warehouse processes, stock controls and warehouse management systems.
• Scalability: Experienced 3PL providers can offer additional fulfilment capacity as order volumes increase, helping brands scale without immediately expanding their own warehouse operation. Read our blog on how to scale without losing control.
• Team productivity: Outsourcing fulfilment can let internal teams focus more on commercial, customer, and growth activities rather than day-to-day warehouse operations.
• Brand reputation: Fulfilment problems can quickly affect customers, so they require strong management to reduce the risk of reputational damage. 

Fulfilment isn’t just another warehousing function; it can directly impact customer retention and brand growth. 

What does in-house fulfilment look like?

With in-house fulfilment, the brand retains responsibility for managing its own core fulfilment operation.

Benefits of in-house fulfilment

Complete operational control and oversight of customer orders

Complete operational control means you have direct visibility into all orders and inventory so that you can make decisions quickly.

Potentially lower costs at lower volumes

An in-house operation can be cost-effective at lower volumes, particularly where existing premises and staff can absorb fulfilment activity. However, brands should consider the full cost of labour, premises, technology, equipment, packaging and management time when comparing models.

Bespoke customer experience

In-house logistics teams know their audience and know how they may react to changes. In-house teams may sometimes find it easier to create custom packaging and offer a more personalised approach through handwritten messages and the inclusion of samples.

Challenges with running fulfilment in-house

Warehouse space limitations

As order volumes and inventory increase, warehouse space can become a significant constraint.

Recruitment and management of teams

With in-house fulfilment, you are fully responsible for your teams, including training, hiring, retention and managing absences. This can all contribute to additional pressure on brands.

Systems and technology

As brands grow, their systems and technology must adapt with them. This often makes them more complex, which can be a lot for in-house teams to manage.

Carrier management

In-house teams often have to work closely with carriers to manage multiple services, rates, collections and performance, which takes time.

Seasonal demand

Many brands have seasonal peaks, such as Christmas and Black Friday. Still, they may struggle to justify permanent increases in warehouse space, equipment, and staffing to accommodate demand that lasts only a few weeks or months.

Returns

As order volumes increase, the absolute number of returns will typically increase if the return rate remains broadly consistent. Effective returns management is important for maintaining customer satisfaction and minimising operational and cash-flow disruption. Read our blog on reverse logistics and returns management explained.

What does a 3PL actually do?

A 3PL provider can support brands with a range of services, including warehousing, inventory management, contract packing, carrier management, reverse logistics solutions, reporting, eCommerce integrations and order management. 

By working with a 3PL service provider, you can reduce internal pressures while retaining oversight through systems, reporting and communication. At Granby, we ensure all clients have access to their own KPIs and performance data, so you can see exactly what’s going on behind the scenes. This transparency allows us to build trust with clients. 

What are the benefits of using a 3PL?

Scalability

A quality 3PL provider can increase fulfilment capacity without requiring the brand to make the same level of direct investment in warehouse infrastructure, equipment and staffing. At Granby, our excellent in-house team is supported by trusted temporary staff during peaks, allowing us to scale with you.

Specialist technology

A 3PL may provide access to warehouse management systems, order management technology and eCommerce integrations without the brand having to purchase, implement and manage all of those systems itself.

Established carrier relationships

Established carrier relationships mean that 3PLs have experience managing multiple services, collections, delivery requirements and carrier performance.

Potentially lower infrastructure costs and faster implementation

Rather than investing directly in additional premises, equipment and warehouse infrastructure, brands can access an established fulfilment operation through a 3PL. The commercial benefit depends on order volumes, storage and distribution requirements, pricing, and the costs of the existing in-house operation.

Supporting growth without property expansion

A 3PL can provide access to additional warehouse and fulfilment capacity without requiring the brand to commit to a larger premises of its own immediately.

Potential drawbacks of using a 3PL

• Less direct physical control for brands
• Dependence on a third-party fulfilment partner
• Communication needs to be strong between partners
• Reporting and system visibility become particularly important
• The right provider needs to understand the brand’s requirements

Granby’s fulfilment services combine warehousing, inventory management, order fulfilment, carrier integration and technology to give eCommerce brands greater visibility and flexibility as they grow.

The 3PL vs In-house decision framework

Question 1: How many orders are you shipping each month?

There is no universal order volume at which a brand should move to a 3PL. The right point depends on factors including SKU count, order complexity, product size, staffing, available space, seasonality and growth rate. Use the following volume bands as a starting point rather than fixed thresholds.

Under 500 orders

• In-house may remain practical for brands shipping fewer than 500 orders
• Existing premises and staff may be sufficient
• Fulfilment may remain manageable, particularly where SKU count and order complexity are relatively low

500-5,000 orders

• Start assessing operational efficiency
• Staffing, space, technology and peak capacity become increasingly important
• A third-party logistics provider may start to make commercial and operational sense

5,000+ orders

• At higher volumes, the efficiency, technology and scalability of the fulfilment operation become increasingly important

Question 2: Is fulfilment distracting you from growth?

For many growing brands, fulfilment challenges can significantly distract from growth. Ask yourself:

• Are we spending too much time packing orders?
• Is the commercial team getting pulled into warehouse tasks?
• Is logistics taking attention away from sales and marketing?
• Are warehouse problems regularly reaching senior management?

The cost of fulfilment isn’t just monetary. It can also cost businesses in other ways, such as management time. Read our blog on what 3PL providers cost.

Question 3: Are you running out of space?

Warehouse space can become a significant challenge for growing businesses. Watch for several warning signs.

• Stock stored in multiple locations
• Overflow stock in offices
• Difficulty receiving inventory
• Limited room for growth

Expanding your premises can solve an immediate capacity problem, but it also creates additional fixed costs and longer-term commitments. Depending on the circumstances, outsourcing may provide a more flexible way to increase capacity.

Question 4: Can your operation handle peak demand?

Many brands experience seasonal demand peaks, such as Christmas, Black Friday, new product launches, media coverage and influencer campaigns. You’ll need to consider whether your current set-up could handle a significant increase in orders tomorrow.

If the answer is no, explore whether the business has the resources to build that capacity permanently or whether flexible 3PL capacity would be more appropriate.

Question 5: Do you have the technology you need?

Technology is vital in fulfilment and brand growth. Many brands struggle to keep up with demand, which can significantly impact operations. Consider how your brand currently handles:

• Real-time inventory visibility
• eCommerce integrations
• Order tracking
• Performance reporting
• Returns management

Many growing brands underestimate the technology investment needed to scale efficiently. Granby’s fulfilment operations are supported by integrated warehouse and order management platforms that provide visibility across inventory and order activity. Find out more about our advanced, in-house-built platforms.

A simple traffic light assessment

This isn’t a prescriptive scoring system. Instead, use it as a quick way to see whether your current fulfilment model still supports your business or is starting to become a constraint.

Stay in-house (Green)

Suitable when:

• Low order volumes
• Stable demand
• Available warehouse space
• Fulfilment is not distracting management

Review your options (Amber)

Suitable when:

• Your eCommerce business is growing quickly
• Experiencing seasonal peaks
• Team spending excessive time on fulfilment

The key here is to start researching logistics partners before the operation becomes a problem.

Consider a 3PL (Red)

Suitable when:

• Space is constrained
• Service levels are slipping
• Growth is being restricted
• Significant investment would be needed to scale internally

Common fulfilment mistakes growing brands make

Many growing brands encounter avoidable fulfilment challenges. Recognising the warning signs early can make it easier to review your options before capacity or service levels become a problem.

Waiting until capacity is exceeded

Brands that wait until a crisis point often find it much harder to transition to a new model than those that research and make the change earlier. Using alternatives means you can grow your brand more steadily with the right support in place.

Only considering storage costs

Storage costs are an important part of your strategy, but they don’t tell the whole story. Brands often overlook the total cost of eCommerce fulfilment, which includes the following elements.

• Labour
• Premises
• Equipment
• Software
• Packaging
• Carrier management
• Returns
• Management time

Ignoring technological requirements

Manual processes work well for small business operations, but as your orders rise, they can become inefficient. Working with a 3PL can reduce the need for a brand to build and maintain its own warehouse technology infrastructure, although integration and implementation still need to be considered.

Underestimating returns

Returns can involve more than processing a refund. Depending on the product, returned items may need to be inspected, quality-checked, restocked, repackaged, repaired or safely disposed of.

Expanding too early

Many brands expand too early, which can drive up costs and add stress for business owners in the long run. A 3PL can allow brands to increase fulfilment capacity without taking on the same level of direct investment in additional premises, equipment and warehouse infrastructure. Contract terms and minimum commitments will vary between providers, so these should be considered when comparing options.

Choosing a 3PL only on headline price

The cheapest option is not always the best, and a lower headline price does not necessarily mean lower long-term costs. When comparing quotes, ensure you consider the following elements.

• Service levels
• Technology
• Integration
• Scalability
• Carrier options
• Reporting
• Returns
• Communication
• Implementation process

Is hybrid fulfilment the answer?

Many brands don’t move from 100% in-house to 100% outsourced overnight. Some brands keep some activities in-house while outsourcing others, allowing brands to retain control over selected activities while outsourcing areas where a specialist partner can add capacity or expertise. The right split depends on the brand’s products, channels, customer experience requirements and operational capabilities.

Potential hybrid approaches:

• eCommerce outsourced, wholesale retained in-house: Useful where B2C and B2B fulfilment have different requirements.
• Peak fulfilment outsourced: Allows for additional capacity during Black Friday, Christmas or launches.
• Warehousing outsourced, customer service retained internally: The brand maintains direct ownership of the customer relationship while a 3PL manages physical fulfilment.

Hybrid models can be highly effective because they allow a gradual transition, lower risk, more control over key activities, and greater flexibility during growth periods.

A good 3PL should work with you to understand your operational requirements and identify where it can add the most value. As your brand grows, your fulfilment model may need to evolve with it.

How to make the final decision

Ask:

• What are our current monthly order volumes?
• How quickly are they growing?
• How much warehouse capacity do we have?
• What does fulfilment actually cost us today?
• How much management time does it consume?
• Can our systems support the next stage of growth?
• What happens during our busiest periods?
• How much investment would scaling in-house require?
• What level of control do we need to retain?
• Would a 3PL give us greater flexibility?

Before deciding, consider the total fulfilment cost, operational impact, and growth potential of each model, rather than just the headline price.

Choosing the fulfilment model that supports your growth

Neither in-house fulfilment or 3PL fulfilment is inherently better; the right choice depends on the brand’s current needs, operational capabilities and growth plans.

In-house teams can offer control and flexibility at the right stage, but a 3PL can provide the infrastructure, technology and scalability without requiring the brand to build everything itself. The best action is to consider alternatives before they become a necessity, when fulfilment challenges may be holding your growth back.

Is your fulfilment operation ready for the next stage of growth? Granby works with growing eCommerce brands to provide warehousing, inventory management, order fulfilment, carrier integration and technology-led fulfilment solutions. Speak to the Granby team to discuss your current operation and explore whether a 3PL model could work for your business.