The deadline for submitting the second quarterly update for clients that are within MTD income tax for 2026/27 is Saturday, 7 November 2026 (deadline day).

MTD income tax quarters are cumulative. Therefore, the second quarterly update will cover the period that: 

• began on 6 April 2026 (or 1 April 2026 where an election has been made to use calendar quarters); and 
• ended on 5 October 2026 (or 30 September 2026 where calendar quarters are used). 

Each quarterly update overwrites the previous update. Therefore, if an error was made in the update for quarter one, it is not necessary to go back and resubmit that update. Instead, if the digital records are amended, the position will be corrected in the submission for quarter two.

How to get help 

Although the agent dedicated line will not be available on deadline day, agents can contact HMRC using webchat (8am to 4pm) or the self assessment general enquiries helpline (9am to 3pm) on the day. HMRC recommends that agents who expect to need HMRC's support do not wait until deadline day to contact HMRC.

Clients new to MTD 

Where a client is engaging with MTD income tax for the first time in the run-up to deadline day, it is important that agents ensure the correct process is followed in order for a successful submission to be made. Depending on the circumstances, this may include getting your client’s authorisation, signing the client up for MTD income tax and linking your software to HMRC.  

As explained in an earlier article, it is possible that HMRC may have signed the client up to MTD income tax on their behalf. In this case, the client will have received a letter from HMRC asking them to access their HMRC online services and to check their details. HMRC will not send the agent a copy of this letter to the agent, but the agent can perform the check on behalf of their client by searching for the client on their ASA (by using the client’s unique taxpayer reference) and then checking the client details. 

First quarterly update is outstanding 

The deadline for submitting the first quarterly update was 7 August 2026. The update should be submitted as soon as possible if it has not been submitted already. Although there is no late filing penalty for the late submission of quarterly updates for 2026/27, there is a legal obligation to submit the updates. ICAEW understands that some software providers may allow for a single update to be made to cover obligations for both quarters.  

Should the client wish to report using calendar quarters, the election must be made in the software before the first quarterly update is submitted for the tax year. HMRC recommends that where the client chooses calendar quarterly reporting, "it is important that they wait until the change is fully reflected in their software before submitting a quarterly update".   

ICAEW understands that HMRC intends to contact taxpayers who have signed up for MTD income tax from April 2026 and are yet to submit their update for quarter one. The contents of the letter will be published in HMRC's MTD agent toolkit in due course. Agents will not receive copies of letters sent to clients.  

Looking ahead 

The deadline for submitting the third quarterly update for 2026/27 is Sunday 7 February 2027. This weekend deadline may pose additional challenges for agents, coming shortly after the 31 January 2027 deadline for submission of the self assessment (SA) tax return for 2025/26. 

Taxpayers with combined gross income of more than £30,000 from any sole trades and property businesses they carried on in 2025/26 will come within scope of MTD income tax from 2027/28 if they are not already within MTD income tax. Agents may wish to consider signing relevant clients up for MTD income tax for 2027/28, or applying for an exemption if appropriate, after submitting their SA tax return for 2025/26.