In collaboration with AAT and ACCA, the ATT and CIOT have produced Engagement letter guidance and proforma templates for use by our members. 

Our thanks are also given to ICAEW and STEP for their contribution to the guidance and proforma templates.  

The engagement letter guidance comprises: 

• Guidance notes, explaining the importance of considering various areas of the client relationship with a view to safeguard against issues
• Proforma letter of engagement
• Proforma privacy notice
• Proforma schedules of services
• Proforma standard terms and conditions of business
• Proforma letter of disengagement

The guidance is also supplemented by a proforma subcontractor agreement for use by practitioners when acting as a subcontractor to a regulated firm engaged in public practice.  This is available for download below.

The proforma letter of engagement, privacy notice, schedules of service, standard terms and conditions of business, letter of disengagement, and subcontractor agreement are intended to be adapted and amended by tax practitioners to suit their own practice.  Please refer to the important note on the front of the guidance which states the basis on which they are provided for member use.

The latest edition of the guidance is dated 3 March 2026 and includes updates made following the last major review conducted in 2018. Please note that the latest version of the guidance (including the subcontractor schedule, and new MTD and ROE schedules) has not been subject to review by legal counsel. CIOT and ATT and all those involved in the preparation and approval of this guidance do not accept any responsibility for any loss occasioned by reliance on the documents. Proforma documents cannot and should not be taken as a substitute for appropriate legal advice.

The Joint Professional Bodies Engagement Letters Working Party will keep the engagement letter guidance under review. Should members wish to comment or have any suggestions for improvements, please email [email protected].

New MTD for Income Tax Schedule update March 2026

An update has been made to the new MTD for income tax schedule that was first published by the Joint Professional Bodies Engagement Letters Working Party in June 2025. This schedule can be used by members with clients who must comply with the requirements of MTD for income tax and is available both below and within the main engagement letter guidance.

Register of Overseas Entities (ROE) Schedule published 18 August 2025
The Joint Professional Bodies Engagement Letters Working Party published a Register of Overseas Entities (ROE) schedule and this is available to download below, and in the main guidance. This schedule can be used by members who have agreed to verify the identities of any beneficial owners or managing officers included in the Register of Overseas Entities, on behalf of their clients. As you will be aware, under the Economic Crime (Transparency and Enforcement) Act 2022, overseas entities that own property in the UK must register with Companies House and must obtain independent verification of their owners and officers and may engage our members to complete this service on their behalf.  Further information about the requirements is available on the ATT website here. To confirm, the schedule does not relate to the provision of Authorised Corporate Service Provider (ACSP) services.

Downloads - See all updates