Providing EPOS solutions to the hospitality sector for over 20 years

How to Integrate A POS System with Your Website

11/09/24

Integrate a POS with your website in this step-by-step guide. Simplify operations, improve payment processes, and sync data seamlessly. Start your integration now!

The integration of a point of sale (POS) can greatly simplify the operations in your restaurant and make the payment process a whole lot more streamlined for customers. In this step-by-step guide, we will take you through the complete process of integrating your POS system into your website, laying out everything from choosing the system to making it live.

Step 1 - Assess Your Current Systems

  • Review your current website, product management system and e-commerce platform to figure out if there is an option to implement a 3rd party POS system and what the requirements are.

Step 2 - Choose a Compatible POS System

  • Based on the insights gained from the first step, choose a POS system that is compatible with your current setup. However, if you're building a new website, you can select the POS system first and then build your website around it. The selected system should be compatible with the e-commerce platform on which your website is based.
  • One of the best POS systems currently available in the UK is 3S POS which is compatible with each and every e-commerce platform — Shopify, WordPress, Wix and everything in between.

Step 3 - Defining Your Integration Strategy

Selecting a suitable POS system ecommerce integration module is very important for smooth functioning between your Point of Sale (POS) system and e-commerce platform.

Built-in (Native Integration)

  • This is usually the easiest and most direct route to POS system integration.
  • It's the POS system that comes built-in with the e-commerce platform you are using. For instance, Shopify POS comes pre-integrated into all Shopify websites.
  • The advantages of native integration include easy setup, auto updates and better support.
  • However, it can lack customisation and functionality.

3rd-party Middleware POS System Integrators

  • This strategy involves using third-party software that functions as an intermediary between your POS and website.
  • A great option when native integration is not suitable.
  • Often allows more flexibility and can integrate multiple systems.
  • Keep in mind, this can add additional cost, and you’ll need technical knowledge to setup or configure.

Third-Party Plugins

  • If you're using a popular CMS like WordPress, Joomla, or Magento, there might be third-party plugins or extensions available for easier integration.
  • This strategy is also fairly straightforward, as all you need to do is install a plugin on your website CRM, and you'll have the POS system running.

API Integration

  • While API integration is the most reliable approach, it's also quite extensive technically. 
  • It requires you to build a custom solution using the APIs of POS and e-commerce platforms based on the documentation provided by your POS provider.
  • It isn't a simple plug-and-play system and requires extensive knowledge of website development and programming.

Factors to Consider When Selecting Your Strategy

  • Technical resources available
  • Budget constraints
  • Level of customisation needed
  • Long-term scalability needs
  • Regular data-sync interims

Many people choose to use an API connection because it can be the most reliable source of connection. Read on to step 4 to understand how you connect an API to your POS system.

Step 4 - Create API Connections

The next step is to deploy the API integration. If you don’t have technical knowledge of website development, we would suggest hiring a web developer to make the process seamless.

Obtain API credentials

  • Sign in to the administrator panel of your POS system and find the API or Developer Tab.
  • Locate the API settings in your e-commerce platform as well.
  • Generate your API keys/client IDs and passwords.
  • Store these credentials securely; they're like passwords for your data.

Set up API Endpoints

  • Determine the API endpoints that would be required for each kind of data exchange (for example, inventory orders, customer data, etc.).
  • Set your integration to use the appropriate URL for each endpoint.
  • Ensure you're using the correct API version, as functionality may change between versions.

Secure Authentication

  • Where available, use OAuth 2.0, as it's much more secure than basic authentication.
  • Encrypt all API communications using SSL/TLS.
  • Wherever possible, use token-based authentication to improve security.
  • Implement IP whitelisting if your systems support it.

Configure Data Synchronisation

  • Select the frequency of data syncs (real-time, hourly, or daily).
  • Whenever you can, add webhooks for live updates.
  • Add error handling and logging to identify issues with sync.
  • In this case, you should implement a solution to manage these conflicts when the data is different in both systems.

Step 5 - Choose Sync Data Points

The data points you choose to synchronise are crucial for maintaining a coherent set of your systems.

Inventory Levels

  • Up-to-the-minute stock updates across all sales channels
  • Establish limits for low-stock notifications.
  • Set guidelines for how to treat backorders or if an item is out of stock.

Product Information

  • Update product names and descriptions along with SKUs and categories.
  • Ensure consistent product attributes and variations.
  • Manage digital assets like product images and videos.

Customer Data

  • Synchronise customer profiles — like contact and purchase data.
  • Install GDPR and other data privacy-compliant laws.
  • Create customer segments to better market.

Sales Transactions

  • Sync order details such as line items, quantities and prices are synced.
  • Update pending, shipped or delivered order statuses on all systems.
  • Manage return/refund orders.

Pricing & Promotions

  • Maintain price uniformity across all channels.
  • Synchronise promo codes and deals.

Bi-Directional Sync

  • Add conflict resolution methods, such as the most recent update wins.
  • Use unique identifiers for each data point to ensure accurate matching.
  • Create alerts for any sync or mismatch failures.
  • Perform routine data audits to ensure the continuity of information.

Step 6 - Payment Integration

Implementing payment processing across your POS and e-commerce platform is crucial for a seamless omnichannel experience.

Choose the Appropriate Payment Gateway

  • Find e-commerce platforms that bridge the gap with your point of sale.
  • Pay attention to things like transaction fees, accepted payment methods and location availability.
  • Examples include Stripe, Square and PayPal, or look for solutions specific to your industry.

Ensure PCI-DSS Compliance

  • Choose a gateway that establishes regular payment methods.
  • Configure the same payment options across both online and offline channels.
  • These could be credit/debit cards, digital wallets (e.g., Apple Pay, Google Pay)  and alternative methods like PayPal or Klarna.
  • Ensure the checkout process is similar across channels for a unified customer experience.

Step 7 - Test the Integration

  • Perform a test transaction on both platforms.
  • Real-time inventory updates and verification.
  • Verify synchronisation of customer data.
  • Ensure consistent reporting across all channels.

Step 8 - Staff Training

  • Deliver extensive training on the new system of integration.
  • Modify standard operating procedures to reflect the new flow of work.
  • Create rules for discrepancies or synchronisation issues.

Step 9 - Launch and Monitor

  • Go live with the integrated system.
  • Analyse operations for 1 to 3 weeks very closely.

Now the only thing left is to optimise the system to ensure seamless operations. If you still have any questions, have a look at the 3S POS frequently asked questions.


For almost 20 years, 3S POS has offered one of the most flexible EPOS systems to international brands such as Caffe ConcertoChaiiwalaHeavenly Desserts, Pepe’s Piri Piri, GDK and thousands more delighted customers.

If you are looking for an Restaurant POS System that will not just help you accept payments but includes staff management, inventory management, multi-site management, loyalty programs, and much more, speak to our sales for a free demo.

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