If you own rental property in Cardiff — whether it is a terraced house in Roath, a flat in Cardiff Bay, or a portfolio spread across Cathays and Grangetown — a significant change to how you report your rental income is almost here. Making Tax Digital for Income Tax came into effect on 6 April 2026 for landlords with qualifying income above the relevant threshold. This is not a minor administrative update. It is a fundamental shift in how HMRC expects landlords to keep records and file their finances.
This guide is designed to cut through the noise and give Cardiff landlords a clear, practical picture of what is changing, who is affected, and what you need to do now.
What does Making Tax Digital for income tax actually mean
MTD for ITSA replaces the traditional annual Self Assessment tax return for landlords whose gross income from property — before expenses — exceeds £50,000 per year. From 6 April 2026, these landlords must use HMRC-compatible software to keep digital records and submit quarterly updates to HMRC throughout the tax year, followed by a final end-of-period declaration.
For many Cardiff landlords, particularly those with multiple properties or higher-value rentals in areas like Pontcanna, Canton, or Cardiff Bay, this threshold is very reachable. With average rents in Cardiff sitting between £1,250 and £1,320 per calendar month in 2026, and rental growth of 7.3% recorded across the city in 2025, gross rental income can accumulate quickly.
The quarterly reporting cycle
Instead of a single annual return, you will submit four quarterly updates per tax year to HMRC through your chosen software. These updates report your income and expenses for each three-month period. At the end of the year, you complete a final declaration to confirm all figures are accurate.
This means your bookkeeping needs to be current, organised, and digital throughout the year — not compiled in a rush the following January.
Which Cardiff landlords are affected in 2026
The 6 April 2026 deadline applies to landlords with gross property income above £50,000 annually. The threshold will extend to those earning above £30,000 from April 2027.
In practical terms, this covers a wide range of Cardiff landlord profiles.
Portfolio landlords in Cathays, Roath and Grangetown
Landlords with multiple properties in Cardiff’s high-demand student and professional rental corridors — particularly CF24 postcodes covering Cathays and Roath — are very likely to be within scope. Strong yields in CF24 and CF11 have attracted consistent investor activity, and landlords with three or more properties in these areas will typically exceed the £50,000 gross income threshold with ease.
Grangetown, which has seen significant regeneration investment and growing rental demand, is another area where portfolio landlords need to act promptly.
Single-property landlords in Pontcanna and Whitchurch
Even landlords with a single, higher-value property should check their gross rental income carefully. A well-presented family home in Pontcanna or Whitchurch renting at £1,500 to £2,000 per month generates between £18,000 and £24,000 annually — below the current threshold. However, those with two properties in these areas, or one property alongside other self-employment income, may find themselves within scope sooner than expected.
Investors around Cardiff Bay and the city centre
Cardiff Bay and the city centre apartment market remains highly active, driven by professional contract holders and the continued growth of Cardiff as a business and cultural hub. Landlords with two or more Bay apartments, or a mix of city centre and suburban properties, should review their gross income position without delay.
What records need to be kept digitally
MTD requires landlords to maintain digital records of all rental income received and all allowable expenses incurred throughout the year. This includes:
Rental income from each property, management fees paid, repairs and maintenance costs, insurance premiums, mortgage interest (subject to the existing tax relief rules), letting agent fees, and any other allowable property expenses.
Records must be kept in HMRC-recognised software. Spreadsheets are only acceptable if they are linked to a bridging tool that can communicate with HMRC’s systems. Dedicated landlord accounting platforms and cloud-based bookkeeping software are the most straightforward solutions for most landlords.
Compliance in Wales: the wider picture for Cardiff landlords
Cardiff landlords already operate within a robust compliance framework specific to Wales. The Renting Homes (Wales) Act 2016 governs the relationship between landlords and contract holders — the correct legal term in Wales — and all occupation contracts must meet prescribed standards.
Rent Smart Wales registration and licensing remains a mandatory requirement for landlords and letting agents operating in Cardiff and across Wales. Ensuring your Rent Smart Wales licence is current, your occupation contracts are compliant, and your property records are well maintained all feed into the same principle that MTD reinforces: organised, transparent, and properly documented property management.
MTD does not sit in isolation. It is one further layer in a compliance landscape that Cardiff landlords are already navigating. Having your records in order across all areas — from occupation contract administration to digital tax reporting — protects you and your investment.
How Martin & Co Cardiff can help
At Martin & Co Cardiff, we work with landlords across the city every day — from single-property owners in Whitchurch to portfolio investors with properties across Roath, Cathays, and the Bay. We understand that compliance demands on Cardiff landlords are growing, and we are here to make the process straightforward.
Our managed services are designed to give landlords complete peace of mind. From detailed monthly financial statements that make digital record-keeping far simpler, to expert guidance on the full compliance picture in Wales, our dedicated local team is your single point of contact for everything connected to your rental property.
Martin & Co has over 30 years of experience in residential lettings and manages more than 41,000 properties across the network. We let 370 new properties every week, and our compliance expertise is a core part of everything we do — not an afterthought.
Whether you need full property management, a rent collection service, or simply want to understand how MTD affects your specific situation in Cardiff, we are ready to help without any fuss.
Steps to take now ahead
Check whether you are within scope
Add up your gross rental income across all properties before deducting any expenses. If you are above or close to £50,000 annually, you need to act now. If you are below £50,000 but above £30,000, plan ahead for the April 2027 extension.
Choose your MTD-compatible software
HMRC maintains a list of approved software providers. Research your options and select a platform that suits the size of your portfolio and your preferred way of working. Set it up before the deadline so you are not scrambling in June.
Review your record-keeping habits
If you currently keep records in paper form or informal spreadsheets, now is the time to transition. Your letting agent’s monthly statements are a valuable starting point — ensure you are retaining and categorising all income and expense documentation throughout the year.
Speak to a qualified accountant
MTD is a tax compliance matter, and while this guide provides a practical overview, individual circumstances vary. A qualified accountant with experience in property income can advise on your specific position, software choices, and year-end obligations.
Cardiff’s rental market in 2026: why getting this right matters
Cardiff’s rental market remains one of the most active in Wales. Average rents between £1,250 and £1,320 per calendar month, strong yields in CF24 and CF11, and continued investor demand around Cathays, Roath, and Cardiff Bay mean that property investment here continues to deliver real returns.
Getting your compliance right — including MTD — protects those returns. Penalties for non-compliance with MTD obligations can be significant, and the reputational and financial cost of getting it wrong is not worth the risk when the steps to get it right are straightforward.
Ready to simplify your Cardiff property journey?
Making Tax Digital is one more reason why working with an experienced, compliance-focused letting agent in Cardiff makes sound financial sense. At Martin & Co Cardiff, we take the complexity out of property management so you can focus on what matters — your investment.
Book a free valuation of your Cardiff rental property today and let our local team show you how we can add real value to your portfolio. There is no obligation, and our market appraisals are completely free.
To speak with our Cardiff team about your property, your compliance questions, or how our managed services can support you ahead of the MTD deadline, get in touch with Martin & Co Cardiff directly. We are here to help, every step of the way.
