CHG1300 - Sharing information and handling enquiries from the Adjudicator’s Office
Source: gov.uk (2025-03-21)


Key principles
- The Adjudicator and the Adjudicator’s Office (AO) provides an independent impartial review of complaints. HMRC must support this process so that the AO can provide fair and impartial decisions and effective resolution for our customers who have escalated their complaint to them.
- HMRC and the AO must engage with each other to resolve any areas of disagreement and factual inaccuracy. Through that communication we can learn any lessons that the AO bring to HMRC’s attention.
- The AO review cases independently and where possible, will self-serve from HMRC systems. It is therefore vital to update HMRC systems and CHART with comprehensive notes.
The process:

When a complaint is received by the AO

When a complaint is received by the AO, and accepted by them as appropriate for investigation, the AO will email a copy of the customer’s complaint to the appropriate department in HMRC. This is for information only and no response is required at this stage. It should be logged as an AO complaint on CHART.

The AO investigation

The AO investigator will begin their investigation by considering the evidence provided by the customer. They will also access CHART to see the customer’s tier 1 and tier 2 complaints and the responses by HMRC. The investigator may also gather further evidence by accessing HMRC systems and reading relevant guidance.

Once the AO investigator has completed their initial assessment of the evidence, there are three possible outcomes:
- The AO needs further information before they can make their decision
- The AO considers that they have sufficient evidence to fully uphold, or partially uphold the complaint.
Note: In both the above , the AO should share their intention to uphold the complaint with HMRC before they share their recommendation with the customer
- The AO have sufficient evidence to not uphold the complaint and have not identified any significant learning points for the department
The AO needs further information
- If the AO needs further information, they will make an initial enquiry by sending an email to a nominated inbox or complaints team.
- The enquiry will include, in all cases, the AO investigator’s definition of the customer’s complaint and where they have reached a provisional conclusion to uphold any part of the complaint the AO will outline their reason. This will help the HMRC complaint handler understand the context of the enquiry.
- The request will ask specific questions where the AO have not been able to self-serve from HMRC systems and guidance.
- The business area must provide a dedicated complaint handler to help the AO investigator with their enquiries. In most enquiries we can provide a full response within the service level agreement of 10 working days. If the matter cannot be resolved in that time, advise the AO of the likely response timescale, and keep them updated regularly. However, the AO may decide to make a final decision without our response
- It is best practice for our departments to talk to one another. You should contact the AO investigator by telephone to discuss; how they want the response to the enquiry; any potential misunderstandings; identify any factual inaccuracies; gain an understanding of a provisional conclusion; and discuss any lessons to be learnt.
- HMRC Complaint handlers should clearly note the details of the enquiry on CHART, providing evidence of consultation with colleagues, Central Complaints Advice and Support Team (CCAST) and Policy teams where appropriate. This will make it clear that all relevant HMRC business areas have been consulted about the case to gain the right outcome for the customer.
- Where the AO’s provisional conclusion has not been shared as part of the enquiry process, their office should share their intentions, with HMRC, if they propose to uphold any part of the complaint. If the AO proceed to make a recommendation without HMRC having the opportunity to address what you consider to be fundamental errors with the interpretation of legislation and guidance or there are factual inaccuracies, you should discuss the matter internally and if appropriate ask CCAST for advice
- HMRC complaint handler’s will be able to respond to most enquiries without additional support, but we have outlined below what support is available to you in exceptional circumstances
Case conferencing where additional support is required during the enquiry or HMRC likely not to agree with the recommendation
- We are committed to accept the Adjudicator’s recommendations wherever possible. However, sometimes (although this is likely to be rare) HMRC may not accept the proposed recommendation. If there is an indication that HMRC and the AO do not agree the proposed recommendation, you should ask colleagues in your business area for a case conference to discuss the case before responding.
- If during the internal business case conference, you discover that you need additional support (because of complexity or contentiousness for example), then please contact CCAST within 3 days of the AO Enquiry being received.
- CCAST will support you to provide advice to include in your response to the enquiry.
- You will normally be given advice to enable you to respond within the 10 working days timeframe required by the AO. If the matter cannot be resolved in the timeframe, keep the AO updated with likely timescales for a response. However, the AO may decide to make their final decision without our response.
- You should evidence that you have completed the review with colleagues, CCAST and policy colleagues where appropriate, on CHART. This will make it clear that the relevant HMRC business areas have been consulted about the case to get the right outcome for the customer.
- If the AO proceeds to make a recommendation without you having had the opportunity to address what you consider to be fundamental errors in the interpretation of legislation and guidance or there are fundamental factual inaccuracies, you should discuss the matter internally and you may wish to ask CCAST for advice.
- If you decide a case conference is required, contact the AO to arrange a discussion. Do this on a case by case basis. This will support the AO and HMRC colleagues to focus on each individual case. Remember this is also an opportunity for HMRC and the AO to learn lessons from good complaint handling.
- You should not contact the AO simply because you disagree with the recommendation.
The AO consider they have sufficient evidence to fully uphold, or partially uphold the complaint or have identified a significant learning point

Where an enquiry has not been made by the AO to HMRC
- If the AO will be fully or partially upholding their complaint, and they do not need to make an enquiry, they will send HMRC their complaint definition, proposed decision and rationale for making the decision. The AO share this information to give HMRC the opportunity to provide any technical representations or supporting evidence that the AO may not have considered during their investigation. Importantly, the AO will not send their recommendation to the customer at this time.
- HMRC has 10 working days to provide a full response. If you think you will require further advice from internal teams, you must keep the AO investigator informed of your actions to avoid the recommendation being issued after 10 working days, without the opportunity for HMRC to respond.
- If you need additional support, follow the case conferencing process above.
- Note any lessons to be learnt and forward them on through normal business channels. Look for an opportunity to advise the AO about lessons learned actions taken.
The AO has sufficient evidence to not uphold the complaint and have not identified any significant learning points for the department

Look for any lessons to be learnt and consider providing feedback. Even though the complaint has not been upheld, we should always look for any learning opportunities