A HubSpot Integration Guide

For small businesses, the HubSpot CRM platform provides extensive functionality in one well-connected platform. While it is comprehensive, there are other business functions you rely on to service your customers and deliver your products or services. For instance, if you are a manufacturer you may use enterprise resource planning (ERP) software, connect HubSpot with your accounting software, or import data from an eCommerce platform. 

Three ways to integrate CRM software with HubSpot

The easiest way to use HubSpot is to rely on the core CRM to manage your marketing, sales, and service data. The applications revolve around the CRM and all functions are fully integrated. Many companies use another CRM system like Salesforce, NetSuite, or Zoho to manage their customer data and use the HubSpot Marketing and Sales hubs. These are common integrations and HubSpot has pre-configured connectors built for these situations. However, these integrations need to be managed and data transfer rules need to be established to prevent common problems—duplications and overwritten data. Sync errors are a common problem requiring constant attention since they prevent data transfer between HubSpot and the CRM.

In other cases, an out-of-the-box solution may not be available. There are integration tools like Zapier that act as intermediaries between HubSpot and your other tools. These solutions are not quite as easy to use as a HubSpot Marketplace solution, but you won’t need a developer to create the connection.

When to use a custom integration

When these two solutions do not solve your problems, then you will need to work with developers to create custom connections between your software tools. Many companies have homegrown solutions that developed over many years. These solutions are complex since they are custom-built for the organization, and integrations need to be thoroughly planned and tested.

Reasons for Integrations

Automation is the top reason organizations choose to integrate different applications. Manually retyping data exposes your data to errors caused by human error. By integrating applications, the data is entered once, often by the prospect or customer, and not touched by internal hands. Automation also speeds up business processes and maintains data security. Common customer data is used throughout the organization from the time marketing receives an inbound lead, through the sales process, it is entered into a billing system and product order data is often used as the basis for manufacturing and logistics processes. Since all of these requirements use different applications, custom integrations keep the connections working.

Custom Integration Challenges

Standing up a new HubSpot instance is like building a new house. There is a standardized process that everyone understands. A custom integration is similar to renovating an old house. You never know what you find behind the walls. There may be custom code, complex data relationships, and unknown issues that are not revealed until they are discovered. Experienced data architects and developers can recognize issues before they occur saving the project and the client time and money.

Project scope and creep

Costs are always an issue with custom projects and can quickly get out of control if the client and agency don’t work closely together. Often problems are not encountered until late in the project during testing. Then both parties need to make decisions about the project’s direction. How important are the changes? Do you need additional work, but there isn’t enough money in the budget? Change orders, also known as project creep, also increase costs. These happen when the client changes their mind and requests work that wasn’t defined in the original scope. 

Good project management and communications will alleviate most issues, so it is important to have a project manager who is proactive and brings up issues when they occur. This will save time as the project moves closer to implementation.

Matching data types

The HubSpot CRM has hundreds of standard properties (aka fields), and each property is defined by a property type. Most properties are text or numeric types, but other properties include dropdown (i.e. pick lists) lists, check boxes, and yes/no buttons. When importing or integrating data, it is critical to define the relationships between properties and match property types. For instance, if property options aren’t matched, then synchronization errors occur and data is transferred. 

Here is an example:

Property: Job Seniority

Property Type: Dropdown

Property Options:


HubSpot CRM

Other CRM












In the example above, the developer and client must determine which option to choose, the Senior or Executive. It seems like a simple problem, but if the two CRMs have many dropdown lists, these mismatches can be missed and cause problems after deployment.

API Usage

An Application Programming Interface, commonly known as an API is the language developers use to connect two software programs and transfer data between them. Each time software requests information from another program, it creates an API call. Most software companies limit the number of API calls made during a certain timeframe and charge for that connection. These restrictions increase the cost of custom integrations and need to be determined during the original statement of work. 

HubSpot requires OATH authentication to maintain the security of your data and according to the HubSpot Integration Guide, “For OAuth apps, each HubSpot account that installs your app is limited to 100 requests every 10 seconds. This excludes the Search API.

Types of data synchronization

Data flow is another critical aspect when designing a custom integration. Do you want data to flow one way from one application to another, or does the data need to flow back and forth (aka two-way or bi-directional synchronization)? If you want both CRMs to automatically update each other, then choose two-way synchronization. If you do not need one source to be updated, then one-way synchronization is a better fit. 

The custom integration process

Designing the custom integration requires advanced planning. Creating a visual model helps the developer and client understand the relationships between the applications, how the data is going to flow, and the rules required to avoid duplication and data errors.

Below is an example from Inbound AV that shows the relationships between a fundraising application (Raisers Edge), a data warehouse, Shopify, and HubSpot. Note the arrows indicate which way the data is flowing and which applications require two-way synchronization.


Source: Inbound AV

Testing and validation

As developers create custom connections, it is important to maintain a consistent testing process. It is important not to wait until the end of the project to begin testing, but rather, test as each step is completed. User Acceptance Testing (UAT) is the last step in the development process when the developer and the client tests the integrations together to prove that the solution is working. The client must also validate that the data being transferred is correct and located in the correct properties. 

Maintaining HubSpot integrations

Once an integration is set up between HubSpot and third-party applications, the job is not finished. Every time a new property is created or a dropdown list changes in one application, the other application needs to be updated. It is important to keep up with this ongoing maintenance, otherwise, you will create synchronization issues that will stop data from transferring. Change requests should be tracked through a project management or help desk ticketing system as part of the documentation process. This will allow testers and future developers to debug issues.

How to Select a HubSpot Custom Integration Vendor

The first step is to select an integration vendor who is experienced, and preferably certified, by HubSpot to perform custom integrations. HubSpot is a complex platform with multiple applications, a unique programming environment, and unique data structure. HubSpot developers are trained to work with the HubSpot tools and understand the nuances and limitations of the platform. It also helps that the integration vendor has experience with other major CRM, financial, and ERP applications. 

Keys to successful custom HubSpot integrations 

Custom integration projects help organizations improve internal processes and reduce costs and data redundancy. These projects are more expensive than out-of-the-box solutions but tie together critical systems in larger organizations. It is important to identify integration challenges, use visual design tools, and test integrations while they are being developed. Keep track of change orders to avoid project scope creep and budget increases. To ensure successful integration, work with certified HubSpot custom integration consultants.


InboundAV is a full-service business development agency and certified HubSpot Custom Integration Partner. We help growing businesses develop game-changing strategies and the automated processes needed to help you scale. As a HubSpot partner, we provide a full range of services to support your operations team, including custom integrations, automated workflows, onboarding, training, and ongoing support services.

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