A defining week for UK accountants, with MTD for Income Tax now 44 days away from its start date, HMRC confirming the launch of its mandatory tax adviser register, fresh questions emerging over how ISA products will need to be presented to clients from 2027, and a timely warning from HMRC’s Digital Security Working Group about a rise in email scams targeting agents directly.
Here is everything that matters this week.
Weekly News & Updates Summarised
- MTD for Income Tax starts 6 April. Clients earning above £50,000 must be onboarded onto compatible software now.
- HMRC’s mandatory tax adviser register launches 18 May. Registration deadlines run through to early 2027.
- Cash ISA limits drop and ISA interest rules change from April 2027. Client savings advice may need updating.
- Scam emails impersonating HMRC are targeting agents. Go directly to GOV.UK and do not follow unsolicited links.
44 Days to MTD for ITSA: What Still Needs Doing
The clock has run out for most preparation conversations. From 6 April 2026, Making Tax Digital for Income Tax Self Assessment becomes mandatory for self-employed individuals and landlords with qualifying income above £50,000. With 44 days remaining, the focus for accountants shifts entirely from awareness to implementation.
From that date, affected clients must:
- Maintain digital records of all income and expenses
- Submit quarterly updates to HMRC through compatible software
- Replace the single annual Self Assessment return with four quarterly updates, plus a final declaration submitted after the tax year ends
For any client not yet onboarded, time is critically short. Priority actions this week include confirming which clients fall into the April 2026 cohort, getting software set up and authorised, and ensuring digital record-keeping is in place from day one.
Cost is not always a barrier to the right software. Our guide to the top nine HMRC-approved free MTD software options covers what each tool offers and which client types they suit best.
HMRC Mandatory Tax Adviser Register: Key Dates Confirmed
HMRC’s new mandatory register for tax advisers goes live on 18 May 2026, replacing the existing method of signing up to use HMRC services. The scope is broad: any individual or firm that interacts with HMRC on behalf of a paying client is considered a tax adviser under the new rules, regardless of how they describe their work.
Here’s the key registration dates at a glance:
- 18 May 2026: Register opens for advisers without an existing agent services account
- 18 August 2026: Deadline for those with an existing self assessment or corporation tax agent account
- 18 November 2026: Registration window opens for payroll-only providers
- Early 2027: Absolute final deadline for all advisers
Advisers who already hold an agent services account do not need to register it again but will be contacted through it for further information. Non-compliance carries penalties and stop notices.
Who Is Exempt
In-house corporate tax teams, payroll staff employed directly by a company, VAT representatives, insolvency practitioners, and charitable tax advice services fall outside the scope of the register.
Professional bodies have flagged that sector-specific guidance remains incomplete, and further clarification from HMRC is expected before May.
HMRC has published guidance on who needs to register and when. Check if and when you need to register as a tax adviser with HMRC on GOV.UK.
ISA Cash Interest Set to Become Taxable: What Clients Need to Know
From April 2027, the annual cash ISA limit for savers under 65 drops from £20,000 to £12,000. The stocks and shares ISA limit stays at £20,000 until April 2031, with the stated aim of steering savers toward investment-based products.
To close an obvious workaround, HMRC has confirmed that interest earned on cash held inside a stocks and shares ISA will become taxable. This matters more than it might initially appear. Cash moves through these accounts constantly: contributions come in as cash, dividends land as cash, and assets are sold to cash to fund withdrawals. Taxing interest on that cash introduces real complexity and raises genuine questions about whether stocks and shares ISAs can still be described to clients as fully tax-free wrappers.
A full consultation on the draft legislation is expected before April 2027. Accountants advising on savings strategy should monitor how that develops before making any firm recommendations.
HMRC Warning: Email Scams Targeting Tax Agents on the Rise
HMRC’s Digital Security Working Group has flagged a rise in email scams targeting tax agents. The scam email claims to be from HMRC and instructs the recipient to update their anti-money laundering supervision registration details.
Agents should access HMRC’s online services exclusively by navigating directly to GOV.UK rather than following links in unsolicited emails. If an unexpected email, text, or phone call arrives claiming to be from HMRC, do not share any information before verifying it is genuine.
Legitimate HMRC emails will only ever come from an address ending in gov.uk. Recognised domains include:
- @hmrc.gov.uk,
- @tax.service.gov.uk,
- @advice.hmrc.gov.uk and
- @updates.hmrc.gov.uk.
The gov.uk element will always appear at the end of the address, never in the middle.
Suspicious contact should be reported to HMRC directly: forward emails to phishing@hmrc.gov.uk, forward text messages to 60599, or report phone calls via GOV.UK.
Looking Ahead
The MTD start date and the benefits in kind registration deadline are both imminent, making this a period where client-facing action matters more than reading. The email scam warning is worth circulating to your team now rather than filing away. The mandatory tax adviser register launches in May and with sector-specific guidance still outstanding, that conversation is only going to grow louder over the coming months.
