HMRC have introduced a new online service which allows taxpayers and their appointed agents to upload documents to HMRC electronically as part of a compliance check.
The new service, introduced on 3 August 2026, allows taxpayers and appointed agents to securely upload documents to HMRC through a dedicated form where they have received a letter from HMRC's compliance team asking for additional information.
Those wishing to use the service will need to sign in here using their Government Gateway account. Those without sign-in credentials can create them as part of the process.
- The case reference number must be provided during the process, and this should be taken from HMRC's compliance letter. A submission may be delayed if the incorrect number is used.
- Each file uploaded must be 15MB or less and be in an acceptable file format, which includes PDF, JPEG, Word and Excel documents. Only 10 documents can be uploaded at a time, though there is the option to upload more documents as separate batches. Progress can be saved and returned to later.
Once a submission has been made, HMRC will issue a confirmation email containing a submission reference number. HMRC will review the information and contact the taxpayer or appointed agent if any further information is required.
Useful guides on this topic
Sch 36 Information Notices
What is a Schedule 36 Information Notice? When can HMRC issue one? What rights does the taxpayer have when an information notice is issued? What penalties apply for a failure to respond to an Information Notice?
Penalties: Schedule 36 information notices
What penalties apply if you fail to comply with an Information Notice request by HMRC? What are your rights of appeal?
Time limits for tax assessments, claims and refunds
What are the time limits for claiming a tax refund? How far can HMRC go back and raise an assessment? How many years back can a taxpayer appeal? What are the time limits for correcting a tax return?
External link
HMRC: Send documents or information to HMRC for a compliance check - GOV.UK