Hello everyone,
We are integrating our software with the Companies House accounts-submission service and would appreciate guidance on how to generate the transaction_id correctly.
Our software currently creates a 22-digit numeric ID, for example:
20XXXXXXXXXXXXXXXXXXX1
We increment this value by 1 for each submission. Submissions generally succeed, but we receive the following error for customers who have previously filed using other software:
Error Number: 503
Error Type: fatal
Error Location: Accounts
Error Text: Repeat/non-incremental Transaction ID sent with request - Reject
Could you please clarify:
- What format and generation rules must a transaction_id follow?
- Is the ID required to be unique and incrementing for each company, each software product, or each submitter?
- How should we determine the correct next ID when a company’s previous submission was made using different software?
- Can we retrieve the previous submission’s transaction ID through an API? The IDs shown in filing history appear encoded, and we are unsure whether they represent the same value.
- Is there a recommended way to handle this error and safely retry a submission?
We want to ensure our software generates IDs that comply with the submission requirements and avoid duplicate or non-incremental transaction IDs.