HMRC: VAT Assist
The service compares data added to a customers tax return against information HMRC holds for that customer to provide incisive feedback to help customers submit accurate tax returns.
1. Summary
1 - Name
VAT Assist
2 - Description
The service provides customers with feedback on their completed tax returns, on applicable tax regimes whilst the customer is submitting their return. The purpose is to help customers to submit an accurate tax returns.
3 - Website URL
HMRC Assist is designed to be extensible across different taxes. HMRC Assist for Making Tax Digital for Income Tax is live and promotional material is available now at www.gov.uk/government/publications/find-out-about-hmrc-assist–2 . Additional guidance will be provided to cover HMRC Assist for VAT.
4 - Contact email
Tier 2 - Owner and Responsibility
1.1 - Organisation or department
His Majesty Revenue & Customs
1.2 - Team
HMRC Assist for VAT
1.3 - Senior responsible owner
Head of HMRC Assist
1.4 - Third party involvement
Yes
1.4.1 - Third party
Approved HMRC third party suppliers.
1.4.2 - Companies House Number
N/A
1.4.3 - Third party role
Third party suppliers are used for deployment of risk packages in to the live environment. Analysis of risks and insight are all developed by civil servants
1.4.4 - Procurement procedure type
The Restricted event procurement procedure is used, as it would be a direct award under the SAS professional services agreement
1.4.5 - Third party data access terms
All third parties must have sufficient HMRC security clearance
Tier 2 - Description and Rationale
2.1 - Detailed description
The service compares data added to a customers tax return against information HMRC holds for that customer to provide feedback to help them correct any potential errors in their tax submission. This tool will go live in ~April 2027.
2.2 - Benefits
Helping customers to get their tax returns right whilst they are submitting to HMRC.
2.3 - Previous process
Customers would have to contact HMRC for support and guidance on how to complete their tax returns correctly.
2.4 - Alternatives considered
This is a new process, sending digital nudges in VAT has not been done previously. This is currently our only solution for sending digital nudges in the VAT return journey.
Third party software providers are able to provide some feedback to their customers already, but due to the lack of access to third party data that HMRC holds, suppliers are unable to provide the same level of insight
Tier 2 - Deployment Context
3.1 - Integration into broader operational process
The customer is not required to make any decisions or take any actions pending feedback, it is voluntrary whether they take any actions or not.
The tool provides helpful feedback, tailored to the customers submission including where necessary, links to guidance on how to complete the tax return correctly.
3.2 - Human review
HMRC continously evaluates whether customers are receiving the correct feedback.
3.3 - Frequency and scale of usage
This tool will be available to all third party software that make use of the service. The service will be available to all customers using that third party software, with applicable tax regimes, whilst they submit their return.
3.4 - Required training
No training is needed for the end user (customer) to use the tool.
3.5 - Appeals and review
The tool does not make decisions for the customer but provides tailored feedback to assist them with their tax return submission.
Tier 2 - Tool Specification
4.1.1 - System architecture
The pre-submission VAT Return data is transmitted from third-party software to HMRC via an API. That data is analysed in real time, using a rule-based model, comparing to data held within the HMRC estate. Where potential errors are identified, digital nudges will be transmitted through the API for the third party software to present to the customer. The third party software will relay information back to HMRC, confirming the message was presented to the customer.
4.1.2 - System-level input
Tax submission details.
4.1.3 - System-level output
Feedback to help correct the customer correct any potential errors in their tax submission, including links to gov.uk guidance if/where appropriate.
4.1.4 - Maintenance
This is an annual review of the system’s performance.
4.1.5 - Models
This is a rule-based system.
Tier 2 - Model Specification
4.2.1. - Model name
VAT Assist - Risk packages are developed within HMRCs estate through data analysis undertaken.
4.2.2 - Model version
We haven’t yet launched the VAT Assist Model - it is scheduled for release in April 2027.
4.2.3 - Model task
To identify and nudge customers with the aim of correcting common errors in their VAT return.
4.2.4 - Model input
Presubmission VAT Return data, and data held within the HMRC estate.
4.2.5 - Model output
A digital nudge, in the form of a short plain-English message.
4.2.6 - Model architecture
The pre-submission VAT Return data is transmitted from third-party software to HMRC via an API. That data is analysed in real time, using a rule-based model, comparing to data held within the HMRC estate. Where potential errors are identified, digital nudges will be transmitted through the API for the third party software to present to the customer. The third party software will relay information back to HMRC, confirming the message was presented to the customer.
4.2.7 - Model performance
Testing is performed on previous submissions in isolation to ensure accuracy of rule-based logic and robust review and assurance processes are carried out ahead of deployment. There will be nudge post-deployment reviews to ascertain the frequency of nudges and the applicability to the customers they are sent to. Evaluation will occur to determine the impact to the customer journey. We are conducting user research to test the content of digital nudges, aiming to ensure the messaging is clear, easy to understand, and accessible for customers.
4.2.8 - Datasets and their purposes
Presubmission VAT Return data and data held within the HMRC estate.
2.4.3. Development Data
4.3.1 - Development data description
VAT Return data and data held within the HMRC estate.
4.3.2 - Data modality
Tabular and JSON
4.3.3 - Data quantities
VAT Population
4.3.4 - Sensitive attributes
No
4.3.5 - Data completeness and representativeness
The scope of this service is the digitally enabled VAT population.
4.3.6 - Data cleaning
No
4.3.7 - Data collection
We will collect the pre-submission VAT Return data and the digital meta-data as the customer interacts with our service.
4.3.8 - Data access and storage
HMRC personnel with relevant security clearance - data is stored in line with GDPR retention rules.
4.3.9 - Data sharing agreements
No
Tier 2 - Operational Data Specification
4.4.1 - Data sources
Data comes from the customers submission.
4.4.2 - Sensitive attributes
Tax ID’s, Device IDs, IP Addresses
4.4.3 - Data processing methods
There are business validation rules to validate that the VAT Return is completed in full with values in the correct fields.
4.4.4 - Data access and storage
Data is stored as per GDPR guidelines then permanently deleted when out of the retention period
4.4.5 - Data sharing agreements
No
Tier 2 - Risks, Mitigations and Impact Assessments
5.1 - Impact assessments
All impact assessments have been completed in line with HMRC policy and governance. DPIA has been completed for the project which, amongst other things, captures the build and process of the project including the transfer of data, the reasons for it, between what parties, the impact of it and the security issues, mitigations and procedures in place to adhere to all guidelines associated. This DPIA was completed on 05/09/25 and requires an annual review with the next due in 18 days.
5.2 - Risks and mitigations
There is a risk that the digital nudge may not be relevant to the customer - the risk is mitgated by the robust testing, review and assurance processes to ensure the accuracy of the message. The wording of the message is also clear that the customer is not required to take any action if they are confident that their return is correct or that the nudge does not apply.