File types and formats
Find out about the file formats we use in your invoice.
What file formats do we use in invoicing?
We issue invoices to Shippers as electronic files over our Information Exchange (IX) network. These files are formatted as comma separated values (CSV), using industry agreed formats.
We also provide files that contain lower-level detail to support the invoices. These are known as supporting information files.
Our Xoserve Comprehensive Invoices and Charge Types document sets out which supporting information files we use for each invoice type. Visit our Invoice type, charges & VAT page for more information.
Where to find invoice and supporting information file formats
You can find invoice and supporting information file formats in the UK Link Documentation Library secure area.
If you don’t have access to the secure area, please visit Accessing secure documents.
Try our new file formats search functionality
Our new online functionality makes it easier to quickly find and browse file formats data.
Filter by file type codes, record types, and recipients, and get clickable results presented back to you on a usable webpage.
The new page is being trialled in 'Beta' phase and we’d love to get your feedback to help us make further improvements.
User feedback is essential to help us understand how the new search and filter functionality can be further developed.
Please provide your feedback via email at:
File format principles – Gemini invoices
Unlike transportation invoices, Gemini invoices don’t follow a generic file format.
Each Gemini invoice has its own industry-agreed file format and hierarchy. Supporting information is embedded into the invoice file – there’s no separate supporting information file.
For example, the energy balancing invoice (.IDB) includes supporting information within the same CSV invoice file.
Generic invoice file (.INV) hierarchy
The hierarchy for generic invoice files is formatted into three levels, shown in the diagram below. Each invoice comprises seven mandatory records and one optional record.
How to read generic invoice files
You can find information on how to read invoice files in our INV Generic Invoice file format document. This document is in the UK Link Documentation Library secure area.
If you don’t have access to the secure area, please visit Accessing secure documents.
Need more help?
For more help with file formats, please raise a support request.
Help centre – invoices
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2 December 2025
Customer Induction Day -
18 November 2025
Customer Expert Day (Top Process Rejections)