What Happens If You Start MTD for ITSA Mid-Business Lifecycle?
Many sole traders and landlords who will fall within the scope of Making Tax Digital for Income Tax Self Assessment (MTD for ITSA) already operate established businesses before the rules become mandatory.
From April 2026, taxpayers with qualifying income over £50,000 from self-employment and property will be required to follow MTD for ITSA rules. HMRC has also confirmed that the rules will later apply to additional income thresholds. Under MTD for ITSA, affected taxpayers must:
• send quarterly updates to HMRC
• submit a Final Declaration after the end of the tax year
For many businesses, this means moving from an annual Self Assessment process to more regular digital record keeping and reporting.
This article explains what HMRC’s rules mean for businesses that begin using MTD for ITSA after already operating for several years.
Existing Businesses May Already Have Established Record-Keeping Systems
Many sole traders and landlords already use systems to manage:
• invoices
• receipts
• customer records
• income tracking
• expenses
These systems may include:
• spreadsheets
• paper records
• digital folders
• accounting software
• invoicing apps
When a business becomes subject to MTD for ITSA, HMRC requires digital records to be maintained using compatible software or digital systems that meet HMRC requirements.
This means some businesses may need to review whether their current record-keeping methods support MTD obligations.
MTD Introduces More Frequent Reporting
Under the traditional Self Assessment process, businesses generally reported income annually through a tax return. Under MTD for ITSA, reporting responsibilities change. Affected taxpayers will generally need to:
• maintain digital records throughout the tax year
• send quarterly updates for each income source
• review and finalise figures after year end
• submit a Final Declaration
Quarterly updates are summaries of recorded income and expenses sent through compatible software. HMRC explains that quarterly updates do not replace the need to finalise annual figures later in the process.
Businesses May Need to Organise Income Sources Separately
Some taxpayers have more than one source of qualifying income. Examples may include:
• more than one self-employment business
• self-employment income and UK property income
• foreign property income
• jointly owned property income
HMRC guidance explains that qualifying income from self-employment and property is combined when determining whether MTD for ITSA applies. However, separate digital records are normally required for separate businesses or property businesses.
Because of this, businesses that previously combined records in one spreadsheet or filing system may need clearer separation of income sources under MTD workflows.
Existing Records Still Need to Be Kept
Starting MTD for ITSA does not remove existing record-keeping obligations. HMRC requires businesses to keep records for the required retention period, including records created before entering MTD.
Businesses moving to digital systems may therefore:
• continue storing older records separately
• begin maintaining new records digitally going forward
• use software for current and future reporting periods
HMRC states that records must remain accurate and accessible.
Digital Records Become More Important Under MTD
HMRC’s MTD guidance places significant emphasis on digital records. Digital records may include information relating to:
• income
• expenses
HMRC also allows spreadsheets in some situations, provided the records meet digital record requirements and are digitally linked to compatible software where required. Businesses using manual or spreadsheet-based systems may therefore review whether their existing processes support:
• digital organisation
• ongoing record maintenance
• quarterly reporting requirements
Quarterly Updates Require Ongoing Record Maintenance
Quarterly updates are submitted four times during the tax year. Because of this, businesses may need to maintain records more regularly than under a once-a-year reporting process. This may include:
• recording income throughout the year
• maintaining digital expense records
• reviewing transactions regularly
• separating records by income source
HMRC states that quarterly updates are submitted separately for each relevant business or property business.
Software May Become Part of Day-to-Day Workflows
Under MTD for ITSA, compatible software is used to maintain digital records and send information to HMRC. For some businesses, this may change how invoices, expenses and customer records are managed during the year. Businesses preparing for MTD may therefore review:
• how invoices are created
• how records are stored
• how payment information is tracked
• how income sources are organised
Using HMRC-recognised software may help sole traders and landlords prepare for ongoing digital record keeping and reporting requirements under MTD for ITSA.
Starting Preparation Earlier May Make the Transition Easier
Businesses that expect to fall within MTD for ITSA may choose to review their systems before the rules become mandatory for them. This may involve:
• organising digital records
• reviewing spreadsheet workflows
• separating income sources
• using compatible software
• improving invoice organisation
Preparing earlier may help businesses become familiar with digital workflows before quarterly reporting obligations begin.
Final Thoughts
Many sole traders and landlords entering MTD for ITSA will already have established businesses and existing record-keeping systems.
Under HMRC’s rules, affected taxpayers must keep digital records, use compatible software and send quarterly updates as part of the MTD process.
For businesses already operating before MTD becomes mandatory, this may involve reviewing:
• record-keeping systems
• invoice management
• income source organisation
• digital workflows
