The more technology enhances our everyday lives, the more applications we seem to find ourselves using. The role of technology in accounting isn’t much different. Modern tax practices are encouraged to implement so many digital solutions that “tech stack” has become a staple of industry jargon. 

Digital solutions need to work together. That’s why APIs are so important for any accounting tech stack. Adding the right tax API can improve communication between applications and help your firm stay productive at scale. 

Here’s an overview of what APIs are and what they can do for your tax workflow.

What are APIs and how do they work? 

An Application Programming Interface (API) is a software intermediary that connects two or more separate applications. This connectivity can be leveraged to automate tasks and create a more efficient user experience.

APIs might sound complex, but you’ve probably already used them in some capacity without realizing it. If you’ve ever made a payment with PayPal or Venmo on an e-commerce website, an API facilitated that connection.

You can think of APIs as a waiter at a restaurant. Customers order food that the kitchen will prepare, but there must be a messenger to communicate orders to the kitchen and deliver food to the customers. APIs play a similar intermediary role, sending information to an external program on the user’s behalf and delivering the results.

What types of APIs are available?


Representational State Transfer (REST) is the most commonly used API for modern web applications. REST APIs are defined by their: 

  • Statelessness: No client information is stored on the server between requests. Each request operates independently from previous requests. 
  • Flexibility: REST web services divide several components into independent operations. This gives developers more flexibility to customize the application’s functionality without altering the code of the entire application. 
  • Low bandwidth: REST APIs operate efficiently with less bandwidth than SOAP—another reason why they’re developer-friendly. 


Simple Object Access Protocol (SOAP) APIs provide a more rigid, standardized experience for developers. SOAP APIs are defined by their:

  • Structure: SOAP relies heavily on XML framework that provides a strict set of rules for requests to follow. 
  • Neutrality: SOAP is protocol-neutral, meaning it can be accessed via HTTP, SMTP, TCP, and other protocol types. REST applications are mainly restricted to HTTP. 


Remote Procedure Call (RPC) is the most straightforward form of API interaction. Here’s some extra background on the functionality of RPC APIs: 

  • Unlike SOAP and REST, which transfer data, RPC simply executes processes based on a script. 
  • RPC employs JSON or XML protocols. 
  • RPC APIs are limited in security, capability, and architectural flexibility, but they have a minimal learning curve and are reliable for simple tasks. 


WebSocket APIs facilitate two-way interaction between the user and server. Here’s some extra background on the functionality of WebSocket APIs:

  • With HTTP protocol, the user always initiates a request that the server responds to. WebSocket is a bidirectional protocol with no predefined pattern for requests and responses. Communication can be initiated from either end. 
  • WebSocket does not require a new connection for each message like other APIs. Once the connection is established, messages can be sent and received without interruption. 

Which API protocols are best for tax returns? 

Each protocol has its own situational benefits, but the majority of tax return APIs are organized around REST due to its efficiency and developmental flexibility.

SurePrep has its own REST Developer Portal with built-in HTTP authentication and HTTP verbs. This gives SurePrep clients the option to automate and streamline tasks throughout their 1040 tax process.

How your firm can benefit from APIs 

Processing tax returns in a digital environment creates opportunities for optimization. Can you identify points of friction or redundancy in your accounting tech stack? APIs can often help. As the industry continues to adopt new technologies, APIs will support seamless integration into existing workflows and deliver efficient use at scale.

Keep in mind that some software vendors offer API add-ons for an exorbitant charge. Others provide them for free. Before investing in API efforts, research multiple vendors to find the most productive and cost-effective solutions for your firm.

SurePrep’s Income Tax Developer API Portal is free to all clients. Our customers can leverage API actions to:

  • Initiate binder creation and manage binder details 
  • Download unreviewed workpapers by sign-off level 
  • Pull a full audit report of binder events 
  • Automatically download taxpayer Document Request Lists 
  • Generate missing document reports 
  • Compile lists of documents pending signature 
  • Update account owners automatically 
  • Retrieve billing history  
  • And much more… 

Learn more about the features and functionality of SurePrep’s API.

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