CTC Guarantee Balance API phase 5 testing guide
Learn how to test the compatibility of your software with New Computerised Transit System phase 5 (NCTS5) and CTC Guarantee Balance API v2.0.
Before you start
When you are ready to test your software, first read and understand the CTC Guarantee Balance API phase 5 service guide.
Scheduling your testing
Before the UK NCTS5 goes live, you will need to check that your software is compatible with both it and CTC Guarantee Balance API v2.0. This involves using test scenarios and predefined test data.
Trader Test
Trader Test is a test environment that simulates both automated responses and real-life NCTS experience. This includes the Guarantee Management System (GMS) against which you will be able to run your tests.
For information about accessing the NCTS5 Trader Test environment, see CTC Traders API phase 5 testing guide.
Testing prerequisites
For information about actions that must be completed before testing, see the quick start section of the CTC Guarantee Balance API phase 5 service guide.
UK cutover from NCTS4 to NCTS5
After the NCTS5 service goes live, there will be an NCTS4 to NCTS5 cutover period that will affect in-flight and newly created transit declarations. For information about this, see CTC Traders API phase 5 testing guide.
The cutover period will not affect CTC Guarantee Balance API v1.0 or CTC Guarantee Balance API v2.0. Instead, guarantees will be migrated from NCTS4 to NCTS5 while the UK NCTS4 service is still running, and the NCTS4 service will be used for any guarantee balance check calls to the GMS for the duration of the cutover period.
After the cutover period ends, the UK NCTS5 service will be used for all guarantee balance check calls to the GMS.
Navigating CTC Guarantee Balance API v2.0 documentation
The following table lists the documents for CTC Guarantee Balance API v2.0 and outlines the content and intended readers of each document.
| Document | Content type | Granularity | Summary | Intended readers |
|---|---|---|---|---|
| CTC Guarantee Balance API roadmap (covers NCTS4 onwards) | Functional | High level | Outlines current status of API for each NCTS phase Outlines any development plans for API |
Software developers Technical architects Product managers Business analysts |
| NCTS phase 5 technical interface specification (TIS) | Technical (business logic/rules) | Low level | Captures UK implementation of NCTS5 Shows NCTS5 process flows Lists the message definitions and rules and conditions involved in the exchange of messages between traders and the NCTS for the departure and arrival of transit movements |
Software developers Technical architects Product managers Business analysts |
| CTC Guarantee Balance API phase 5 service guide | Technical | High level | How to use the API How to self-onboard |
Software developers Technical architects |
| CTC Guarantee Balance API v2.0 reference | Technical | Low level | How to use each API endpoint | Software developers Technical architects |
| CTC Guarantee Balance API phase 5 testing guide (this document) | Functional | Low level | How to carry out assurance testing of your application software to ensure that it is compatible with the API |
Software developers Technical architects Product managers Business analysts |
The order in you which you might read these documents can depend on whether you have previous NCTS experience. The following table recommends 2 possible reading orders but you can read the documents in any order you want.
| Suggested reading order | New NCTS users | NCTS4 users migrating to NCTS5 |
|---|---|---|
| 1 | Roadmap | Service guide |
| 2 | Service guide | Technical interface specification |
| 3 | Technical interface specification | Reference |
| 4 | Reference | Testing guide |
| 5 | Testing guide | Roadmap |
Note: If you have NCTS4 experience, it is important that you read the NCTS5 service guide and API reference carefully to understand all of the differences between NCTS4 and NCTS5. Reading only the NCTS5 technical interface specification will NOT guide you about all of the differences between the 2 NCTS phases.
Related documentation
Getting help and support
Before contacting us, find out if there is planned API downtime or a technical issue by checking HMRC API Platform Status and New Computerised Transit System service availability.
If you have specific questions about the CTC Traders API, contact our Software Developer Support (SDS) Team. You’ll get an initial response within 2 working days.
You can also email questions to SDSTeam@hmrc.gov.uk. We might ask for more detailed information when we respond.
Changelog
You can find the changelog for this document in the ctc-guarantee-balance-phase5-testing-guide GitHub wiki.