Substrate is the layer beneath Xero, QuickBooks and Landlord Studio — built for landlords, sole traders and the accountants who file for them, wherever the off-the-shelf software runs out of road.
HMRC isn't asking. Making Tax Digital for Income Tax is a legal requirement, phased in by income threshold over three years. Waiting until your year arrives leaves no time to fix a bad setup.
Mandatory for sole traders and landlords with gross income over £50,000. Quarterly digital updates plus a final declaration by 31 January following the tax year end.
Threshold drops to £30,000. A much larger group of landlords and sole traders is pulled in — including many still running spreadsheets today who assume they have more time.
Threshold drops again to £20,000. At this point MTD covers the large majority of self-employed people and landlords in the UK — not just the largest portfolios.
Miss four quarterly deadlines and HMRC issues a fixed £200 penalty — then another £200 for every late submission after that. Points don't clear quickly either: once you cross the threshold, you need 24 straight months of on-time filing to reset to zero.
Late payment interest runs at the Bank of England base rate plus 2.5% — currently around 7% a year, charged daily on whatever's outstanding. It keeps accruing quietly whether or not a penalty has been issued.
Records must be "digitally linked" from source to submission. A spreadsheet you retype into by hand each quarter doesn't qualify — HMRC treats that the same as no digital records at all.
Quarterly updates must be submitted before the final declaration can go in at all. Falling behind during the year doesn't just risk a fine — it can block the annual filing outright.
HMRC has confirmed a "soft landing" for 2026/27 — no penalty points for late quarterly updates in that first year. It's easy to read that as "no rush." It isn't: digital record-keeping and quarterly submission are still mandatory to reach the final declaration, interest still accrues from the original due date, and the soft landing disappears entirely from year two. The businesses that get caught out are the ones who mistake the grace period for a deadline extension.
Xero and QuickBooks are excellent at what they're built for — quarterly filing for a simple, single-income setup. From April 2026, roughly 2.7 million landlords and sole traders are required to file this way. But "simple" describes fewer clients than accountants would like.
A single place for landlords or sole traders to upload receipts, invoices and rental paperwork — instead of an inbox full of forwarded PDFs. Feeds straight into whatever software the accountant already uses.
For clients running property income through one tool and self-employment through another, we build the connection that keeps both in sync automatically — no more re-typing the same transaction twice.
One screen for the accountant showing every client's filing status, deadline, and outstanding document — regardless of which mix of software each client happens to run underneath.
For clients still keeping five years of records in Excel, we move them onto a properly structured, MTD-compliant setup before their deadline — done once, not scrambled every quarter.
No package tiers hiding what's actually built. Here's the full functional scope of what Substrate delivers.
Upload receipts, invoices and rental documents from a phone or desktop — one link, no login headaches.
Photographed receipts and forwarded invoices get amounts, dates and categories extracted automatically.
Keeps Xero, QuickBooks and Landlord Studio in sync for clients running income through more than one tool.
Income and expenses split automatically by property, so portfolio-level and per-property P&L are both always accurate.
Every client's filing status — filed, due, overdue — visible on one screen, regardless of software mix.
Quarterly update and final declaration dates tracked and chased automatically, per client, without manual follow-up.
Legacy Excel records restructured into digitally-linked, compliant format ahead of a client's deadline.
Live status of what's been filed, what's pending, and what's overdue — pulled directly from the filing pipeline.
Portal and dashboard carry the accountancy practice's own name and colours — not a visible third-party tool.
Separate, permissioned views for accountant staff, the practice owner, and each individual client.
Every document version-tracked and retained to HMRC's record-keeping standard, with a full change history.
Partnerships, foreign property income, and mixed sole-trade-plus-property cases, scoped and built individually.
Your existing software stays exactly where it is. Nothing about your MTD filing changes. We build around the parts it was never designed to cover.
We're not pretending this space is empty. Several well-built products already cover parts of it. Worth knowing who they are before you take our word for anything.
All-in-one platforms are genuinely good software — but they ask a practice or a landlord to move their whole workflow onto someone else's system, learn it, and hope it fits. Most small practices don't have a spare afternoon to evaluate five tools and migrate a client book themselves.
Built-in practice dashboards from Xero, QuickBooks and Sage only see what's inside their own platform — they go blind the moment a client also uses a second tool, which is exactly the messy multi-software situation most real client books are in.
We don't sell you a new platform. We sit down with your actual software mix, your actual client list, and build the specific portal, dashboard, or reconciliation your practice needs — under your name, fitted to what you already run, including the edge cases (partnerships, multi-property, spreadsheet migrations) none of the above fully solve on their own.
One setup fee to build it, a small monthly fee to keep it running. No annual lock-in unless you want the discount for prepaying.
A base platform fee per practice, plus a small per-client add-on — one combined invoice, cancel anytime. An annual prepay option saves roughly 15% for practices that prefer to pay once.
See every client's MTD status — filed, overdue, missing documents — from one dashboard, no matter which software combination each client happens to use.
Multi-property portfolios and mixed-income sole traders stop being the clients you avoid. The reconciliation work that used to eat an afternoon happens automatically.
Clients upload documents directly into a portal that feeds your existing software — no more forwarded PDFs sitting in an inbox until the week before a deadline.
The portal and dashboard carry your practice's name. Clients see it as part of what you offer, not a third-party tool bolted on.
If you own more than one property, or run a rental alongside a business, we set up the system that keeps both compliant without you learning two pieces of software.
If you're still tracking everything in Excel, we migrate you to a compliant setup ahead of your deadline — not a last-minute scramble in the final quarter.
Photograph a receipt or forward an invoice into the portal — it's reconciled and ready for your accountant without you or them re-entering anything.
No more chasing emails back and forth before a filing date. Your accountant has visibility into your records as they're added.
We map what software you or your clients already use, where the gaps sit, and what genuinely needs building versus what's already covered.
Portal, dashboard, or reconciliation — scoped to the specific gap, not a generic package. Delivered by our architecture-led team across London and India.
Existing records move across cleanly. Your accounting software keeps doing exactly what it does today — we connect it, we don't replace it.
Thresholds drop every year through 2028. We keep the system current as HMRC's rules change, so you're not rebuilding it each time.
A 20-minute call — bring your current software stack, we'll tell you honestly what needs building and what doesn't.
Book a 20-minute call