ISO8583 Card Payments Simulator

Test all card payments protocol with the one configurable simulator

Visa MasterCard Amex Diners Discover JCB CUP and custom

validation and comparison, baselining and changes detection

Precision testing of card payment transactions

Build, run, validate, authorize ISO8583 card payment transaction messages

Functional single tests, scenario, regression and High Performance Testing

EMV capabilities, with Pin, Mac, Sessions and keys management  

MAX speed load test: 1000TPS  

Web services   Rest API   Database compatibility, integration via scripting

Simulate any iso8583 card payments protocol

Key features and benefits

Designed from scratch for payments microservices

All card payments protocols

Simplify the test environment by using a single simulator for all testing protocol interfaces.

Flexible protocol configuration, scripting business behavior

All test phases

Fast POC, Smoke and Functional testing, Scenarios and regression testing. Duration and High performance testing

Flexible protocol configuration, scripting business behavior

All environments

Functional testing on Windows, Linux, Mac. CICD on Azure pipelines Aws, Bitbucket.

Duration and High performance testing on VMs and containers

Protected from human error

Create, deploy, share test configuration and test data without human intervention from Version Control (Git) to all test environments.

Ensure same test conditions in all stages automatically

Automatic Analytics

Generate automatically Analytics reports, data exports locally or to another reporting system.

Scripting available for external integrations

Speed 1000 TPS

Designed from the start for long Duration and High Performance testing

Multiple instances possible, parallel execution, on VMs or cloud.

Acquirer, Issuer, Switch, Clearing Simulator

Visa, MasterCard, Bank host, ATM, POS, e-commerce, fixed formats

Simulate Back-end systems, Host, Fraud, Cards and Balances systems

Support Web services, XML, CSV, clearing and NSK enscribe DDL support

Connect to TCP/IP, HTTP, flat files and SQL

In-house customizations of business logic, message format, connections

Web services and clearing formats connected to ISO8583 interfaces

Supporting any Major Debit and Credit brands
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Save cost and a lot of effort

incrementally replace multiple providers solutions

neaPay Simulator Phases

Fast POC

Functional tests


Performance tests

CICD tests


Simplify Maintenance


Simplify Configuration

Version Controlled

neapay iso8583 simulator demo video  
Visa   MasterCard   Amex   JCB   Discover


Technical run of Example setups like Visa and MasterCard in 3 minutes (video)

Go to list of features


Features List

Customer support options


Support Options

Technical Architecture overview



Documentation, Get started guide


neapay ISO8583 payments simulator

ONE simulator for ALL payments protocols


Card Switches Brands

Have the same simulator for all your payments switches: Visa, MasterCard, Amex, Diners, JCB, CUP and many more

POS Acquirer Systems

ATM, POS, e-commerce, mobile

Host Issuing systems

Integrate with Base24, Base24-eps, Way4, Alaric, Postilion, SmartVista and any custom host

+ Web Services and Databases

Web services and Databases with any formats

Clearing Systems testing IPM CTF &more

Any clearing format, switches defined or custom, binary, XML, JSON

Switch any payments device

Easy to Configure

Test Cases via UI or Excel sheets

Easy to import

Keep cards, terminal data and EMV data in Excel sheets

Easy to customize

Business logic in JavaScript

Easy to set up

Message formats in UI, saved in JSON definitions

Easy to run

One click to run a test case and validate

All Run Modes

Run single test, Scenarios, automatic regression and load tests

For payments consultants and specialists

  • Upload and manage test data is in Excel spreadsheets!
  • Card data is easy to configure and import in Excel, from SQL exports for example, or flat files
  • To make a new test case, transaction, just copy-paste a row in excel and edit it
  • Import and configure terminal data in excel, direct form your system's configuration
  • Define message validation fields in Excel also!
  • Message definition in JSON messages with Graphical interface
  • Connections configuration also in JSON with Graphical interface!
  • All configuration maintainable in version control systems, like Git

For payments testers and beginners

  • Run transactions from the Graphical interface with 1 click!
  • Run automatic regressions from the Graphical interface with 1 click!
  • Start a load test with 1 click also!
  • Edit test data like amounts and card numbers in Excel!
  • Adjust messages and connections from the Graphical interface
  • Save logs in any format with a virtual printing function.
  • All regression can be run by the cleaning lady!

Bank Card payments simulator +more

Back-end systems, host, fraud, cards and balances systems

Web services, XML, CSV, clearing and NSK Enscribe files support

TCP/IP, HTTP, flat files and SQL connections

And for all you can customize the business logic in-house

JavaScript transaction building logic!

Get a quote and a live demo

Switch any payments device

CONFIGURATION in-house options

  • message format, fields and data type (UI)
  • connection type, encoding of data (UI)
  • logging and export (UI)
  • ISO8583 data, fields, Excel formulas available [Excel]
  • test cases copy and change [Excel]
  • card import handling [Excel]
  • validation for Mandatory, Optional, Conditional [Excel]
  • validation for length and data type [Excel]
  • clearing and settlement messages (UI)

CUSTOMIZATION in-house options

  • user interface test cases display {js}
  • user Interface interaction with test cases {js}
  • test data handling {js}
  • message building logic {js}
  • message send and receive logic {js}
  • data formatting to connections {js}
  • authorization logic {js}
  • validation logic {js}
  • conversion logic {js}
  • js scripts load -file
<2>Iso8583 simulator Environment You will love having the same simulator for all your connections: Visa, MasterCard, Bank host, ATM, POS, e-commerce.

Visa, MasterCard, Amex

simulated with the standard ISO8583 based package

POS devices, network

various POS protocols, fixed message or ISO0503 based

ATM devices, network

depending on the device handler, NCR, NDC, Diebold

Clearing and settlement

simple fixed formats configurable, as well as XML or JSON

PSP, aggregator

usually via some form of ISO8583 implementation, easy to configure

e-commerce gateways

they usually send some implementation of ISO8583

e-commerce APIs

standard HTTP web service with XML or JSON data

mobile commerce, networks

networks usually come via ISO8583, while devices may send any API form

telephone, mail

simplified ISO8583 or customized messages, SQL to database checks

international, SWIFT, ISO20022

standard SWIFT or custom inter-bank, payments, clearing, cash


Iso8583 simulator Setup Layout

Test Data

All test cases are stored in Excel sheets. So does card data, key data, validation data and authorization rules. Other sources are possible.


Easy UI configuration, stored in JSON format in javascript file, easy version control.


Easy to configure via UI, but also via javascript JSON editing directly, so easy to deliver, store and massively update.

Business logic

javascript is key here. We use it to user menus for transactions, build transaction data, call core features and of course, handle message contents. The user can see all its work.

Authorization logic

Configurable authorization rules and validation are available in Excel, but more logic is built into javascript authorization, like when to do cryptogram checks and PIN validation, or when to override default response codes

neaPay Core

The power of our simulator comes from its script engine, with support for connections, message building and formatting, its look and feel are the UI which makes it all easy, but its heart is the controller which manages it all.

The UI

It is responsible to make it all pleasant for you to configure connections, messages and fields.

The Engine

It is responsible for running the scripts and do the processing.

The Controller

handles the connections, provides and handles data to and from the script engine and UI, as well as files, databases or TCP/IP.

Get a quote and a live demo

Visa Acquirer Issuer simulator

Acquiring from Visa can be easily simulated by our neaPay engine. How does it work? Load the Visa scripts in our simulator engine, the Visa message format, and do not forget the test cases. Make sure you point to the IP and port you need and start firing away those transactions like they came from Visa. Authorize in your system and our scripts will wait for the response to validate.
Visa Issuer is loaded the same way, just use authorization scripts for issuing, and select the connection type to be a server. The scripts know what messages to wait for, process and respond. It is the best way to test your system before going to certification with Visa. You do not want to keep the certification open for too long.

MasterCard Acquirer Issuer simulator

MasterCard Acquiring is just as easy. Load the BankNet scripts, as well as the messages and test cases, point the simulator to your system and run transactions. One by one, in batches or in full regression mode, it is all a matter of choice. All messages go out in parallel and can come back in any order. Just like a real authorization system.

MasterCard Issuing works with the same scripts, but uses the issuer part of them. The logic in the scripts decides that when you select the option to listen as a server.

Diners, Amex, JCB, CUP simulator

Diners, Amex, JCB, China Union Pay? For the engine it is a matter of loading a different script and formatting messages differently. For the tester it is just a difference of test cases. And IP/port.
Acquiring or issuing, that is just an option.
Pre-certification tests with any switch will give you confidence and you will have the flexibility to test beyond the certification test cases.
If you are a switch , you can use our simulator to certify member banks with your switch!

POS, ATM and e-commerce simulator

POS and e-commerce transactions work just as easily. Load the scripts, the transactions and start testing. Or make changes to match your custom interfaces, and then test as much as you want.

Each ATM vendor comes with a different format and it may be a little more complicated. To be honest, if your vendor provides a simulator for the ATM, use that one. If you need something heavily customized, then neaPay's engine will definitely be able to do it. Contact us and tell us what device you have, we might have the scripts for it already. If not, it is never too late to write a new one.

Regression Testing

Ensuring your payments system did not lose any functionality on updates. Check and validate that limits are working just as fine as before, that the accounts are debited and usages are updated. Each of them. A good regression pack can detect whether your limits are working fine, your balances are fine, all your fields are formatted correctly, for each transaction type, and your transactions are approved or declined as before. With that peace of mind, you can proceed to test the enhancements. Our simulators are designed with a regression approach from the beginning, therefore, any new functionality can be easily added to the regression pack, so next time you apply changes, these enhancements will be tested as part of the regression. After a few years, you will have a nice regression pack of a few hundred or thousand transactions, which can be run in less than an hour to check the status of the system, any day or night. You want this, we know you do, and our simulator can do it very well.

Automatic Regression Testing

We know that you need the functionality above and you know you want it executed as soon as possible. What is your estimate for running a complete regression for the system, that covers everything, with 1000 test cases? You may say a week, you may say maybe two, or you may dare to estimate 2 days. We say that takes an hour. Because that is the estimate we wanted in our test plans and we made the simulator that can do that. Once all is set up properly, click the Run and go for a coffee. When you come back, you have your answer.

Performance Testing

Your system must do all the processing at very high speed, so we built a matching simulator, which can run just as fast. We believe that 60 transactions need to be run in 3 seconds, not 30. We hope you agree. So our simulator can run fast enough to be used for performance testing, even without caching features. We have in plan to add a caching feature, which can release hundreds of transactions per second, it will be here soon!

Frequently Asked Questions

What technology and architecture is used?

The Simulator is written in Java, runs on any platform where Java is available. The configuration and behavior are written in JavScript, which is delivered to the customer

Where can it deploy and run? Does it work in the cloud?

Most users run POC, smoke and Functional tests on a PC workstation or Mac, Windows VM, Linux Vm
Regressions are usually run manually on Linux/Windows VMs, or automatically on Azure Pipelines AWS DevOps, Atlassian bitbucket pipelines
Duration testing and High performance testing are usually run on Windows VMs, but available on any OS or in containers.

Can multiple simulators run and perform different simulations?

As a stand alone instance with User Interface, each simulator instance can run its own configuration to perform separate tests.
Several simulators can be run on the same machine, in separate folders, for ISO8583, ISO 20022, Visa, Amex, MasterCard, clearing.
Each simulator is deployed, configured and maintained separately (manually or via git)

How configurable and customizable is it?

All connectivity, message formats, business logic, are usually delivered pre-configured, ready to run, if the customer chooses to.
The customer can change all configuration, format and business logic, on-premise.
All configuration is easy to version-control (via git).

How fast is the neaPay ISO8583 Performance Test Simulator?

The neaPay Card Payments simulator is designed from start from hgh performance testing.
Each release is tested to run at 1000 TPS. Depending on the hardware limitations and cryptographic operations, it can slow down.
This speed is sufficient to satisfy the speed of a whole country processing system. Multiple instances with slower speed are recommended, to simulate multiple transaction sources.

How long will it take to implement a new protocol?

Most common formats are already available. The neaPay card payments ISO8583 simulator can be set up for a POC in a few hours.
Depending on the size of the scope, and number of transaction types, we can get the most of it set up and ready for testing in a few weeks.
Then it can be used for testing for decades. Free Price Quote

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