Four ways to get your shipment data into CDUK: a public REST API, CSV and Excel import, document upload and email intake. Every route lands in the same draft, checked by the same validation and reviewed by your team, then filed directly with HMRC from your own account.
Your ERP, TMS and WMS systems, your spreadsheets and your suppliers' paperwork already hold most of what a customs declaration needs. Integration simply means that information reaches CDUK without anyone typing it again.
Choose the route that suits each flow. Connect your systems through our documented REST API, upload a spreadsheet, drop in supplier documents, or forward an email. You can use one route or all four on the same account.
Whichever way the data arrives, it becomes the same draft in the declaration workspace, checked by the same validation and reviewed by your own team before it is filed directly with HMRC.
Systems that already produce records suit the API, spreadsheets suit import, and suppliers who only send paperwork suit document upload or email. All four end in the same reviewable declaration.
Our public API is documented in OpenAPI / Swagger and open to browse before you sign up. It covers GB CDS import and export, GB Safety & Security (ENS), EU ICS2 and NCTS6 transit, so one connection serves the filings your operation makes.
API access is switched on for your account with our team.
Explore the API (opens in a new tab)Upload a spreadsheet of shipment lines straight into the platform. There is nothing to build.
Upload commercial invoices, packing lists and transport documents such as a CMR, bill of lading or air waybill, as PDFs, scans, photos or Excel. AI document processing extracts the data into a draft for your team.
Forward invoices, packing lists or a CMR by email. AI reads them and drafts the declaration for your team to review.
Whatever the source, the path is the same: data arrives, is mapped and validated, is reviewed by your team (or submitted by your integration where you choose), is filed with HMRC, and the outcome comes back to you.
Through the API, a spreadsheet, a document upload or an email.
Matched to the declaration and validated, so gaps surface before filing.
Your team reviews and submits, or a permitted integration submits.
Filed from your own account, always with full validation.
References and releases recorded, and sent on to your systems.
One draft, one validation, one review step, however the data arrives.
Two separate connections make the exchange work. We operate the first for you. The second links your own data to your CDUK account, through whichever route fits.
We operate the connections to HMRC and to the UK community system providers (CNS, MCP/Destin8 and CCS-UK), so there is nothing for you to build, certify or maintain. See port and CSP connectivity.
Pick the route per flow: the API for your core systems, import for spreadsheets, upload and email for suppliers' paperwork. Our UK team helps with onboarding, mapping and go-live.
The interface is documented publicly in OpenAPI / Swagger, so your technical team can assess it before you commit to anything.
Each capability shortens your build, protects your account or keeps your customs team in control of what is filed.
Sign in with OAuth2 client credentials or a simple API key. Your administrator creates them in the portal and limits each one to the declaration types and actions it needs. Credentials can be edited, revoked and reinstated.
Keys can carry an expiry date, and administrators are emailed 30, 7 and 1 days before. A replacement key can run alongside the old one, so there is no gap in service.
If your system produces its own shape of JSON, build a mapping profile in the portal with no code. Your system sends what it already produces and we translate it. Mapping applies to inbound data only.
The API publishes every field you can set for each declaration type, flagged required, optional or conditional, with a generated example. Developers do not have to guess field names.
A dry-run returns the full validation report without filing anything. It needs no HMRC authorisation, so you can build and test before your account is authorised.
The careful default creates a draft your team reviews and submits in the portal. Where you choose, a credential with the submit permission can create and submit in one step.
Retry a request with the same idempotency key and it never creates a second declaration.
Reference a saved CDS, ENS or ICS2 template, and anything your system sends takes priority over it. Agents, brokers and forwarders can file for the traders they act for, lodged under the trader's account, with a readiness check that confirms HMRC authorisation first.
A published catalogue of more than 100 error codes, each with its meaning, cause and fix, open to browse without signing up. The error format is versioned, so error handling is built once.
Map your fields to our canonical fields, convert values, set defaults and handle repeating goods lines, all in the portal. Then test a sample against full validation before you save. Your system sends its native JSON and names the profile.
| Your field | Our field | Rule |
|---|---|---|
| sender | messageSender | Direct |
| reference | TransitOperation.LRN | Direct |
| type | TransitOperation.declarationType | standard → T1 |
| lines | House consignment items | Repeating group |
Example profile for an NCTS transit declaration
As each outcome arrives from customs, a signed event is sent to your secure endpoint. If delivery fails, we retry, and an endpoint that keeps failing is switched off with your administrators emailed. The full history is always available to fetch.
Current status and the full customs message history can be fetched through the API at any time.
Every error code comes with its meaning, its likely cause and the fix. Because the catalogue is public, your developers can plan error handling before go-live.
| Code | Meaning | Fix |
|---|---|---|
| NCTS.C0030.OFFICE_OF_TRANSIT_REQUIRED | An office of transit is required | Declare the office(s) of transit the movement passes through |
| TEMPLATE.TEMPLATE_NOT_ACTIVE | The template is a draft or archived | Activate it in the portal or reference another |
| RATE_LIMITED | Too many requests for this credential | Back off using the retry-after signal |
A sample of the published catalogue, browsable without signing up.
Routes combine freely on one account. Use this as a starting point, and our team will help you decide for each flow.
| Route | Best when | What you need | What comes back |
|---|---|---|---|
| REST API | Your systems hold the data and volumes are high or regular | A developer, API access switched on, credentials from your administrator | A draft or submission, validation reports, signed outcome events and full history |
| CSV & Excel import | You can export shipment lines from a system or spreadsheet | A spreadsheet of lines, no development | A draft in the workspace, with lines merged into goods items where relevant |
| Document upload | Suppliers send invoices, packing lists and transport documents | The documents as PDFs, scans, photos or Excel | A draft with differences between documents shown for your decision |
| Email intake | Paperwork arrives by email and you want it to start itself | Forward the email with its attachments | A draft CDS or ENS declaration for your team to review |
Every route ends in the same draft, the same validation and the same review.
Our UK team works with you at each stage.
Accounts are activated instantly. Authorise the platform with HMRC from your account settings and you are ready to file.
We enable the API for your account and help you decide which declaration types and actions each connection needs.
Your administrator creates scoped credentials and builds mapping profiles in the portal, with our team alongside you.
Validate and create drafts using real-looking records. Your team reviews them in the workspace, so you see the result before anything goes live.
Switch on webhooks and, where you choose, direct submission. Your team keeps its review step wherever you want it.
The API covers GB CDS import and export, GB Safety & Security (ENS), EU ICS2 and NCTS6 transit. Other services are filed in the platform itself. Tell us which flows you want to automate and we will confirm the best route for each.
Yes. The API is documented publicly in OpenAPI / Swagger, and the error catalogue is open to browse too. Your developers can assess the whole interface and plan error handling before you register.
No. If your system produces its own JSON, your administrator builds a mapping profile in the portal with no code. Your system sends its native data, and we map it to the declaration. Responses and notifications always use the API's own format.
By default, the API creates a draft that your team reviews and submits. Where you choose, a credential with the submit permission can create and submit in one step. You decide this per credential.
As each customs outcome arrives, we send a signed event to your endpoint. You can also fetch the current status and the full customs message history of any declaration at any time, including the original message exactly as sent.
Failed deliveries are retried for about ten minutes. An endpoint that keeps failing is switched off automatically and your administrators are emailed. Nothing is lost, because the status and message history can always be fetched afterwards.
Yes. CSV and Excel import needs no build, and for CDS it can merge rows that share a commodity code and country of origin into goods items. You can begin here and add the API for your highest-volume flows on the same account.
Upload them, or forward them by email. AI document processing reads invoices, packing lists and transport documents and drafts the declaration. Differences between documents are shown for your reviewer, and the service is included free when you file with us.
Your administrator creates and manages credentials in the portal, limits each to the declaration types and actions it needs, and can revoke or reinstate it. Keys can expire with advance email warnings, and a replacement can run alongside the old one. Webhook events are signed with a secret you can rotate.
Filing is pay as you go, with no monthly fee and no minimum volume, and custom subscription plans give volume discounts. Document processing is included free. See pricing or talk to our team.
Browse the API documentation, or tell us about your systems and the flows you want to automate. Accounts are activated instantly, with pay as you go pricing, no monthly fee and no minimum volume. Our UK-based team helps with onboarding, mapping and go-live.
