Keep every property compliant.
Connect your property data. Automate your workflows.
Built for
Plan renewal
Gas engineer
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Tenant · Flat 2
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Match found
Confirming visit
Provider
You
Tenant
Visit day
✓No credit card needed
✓Setup in 2 minutes
✓Cancel any time
Trusted across the UK
MillOS runs your compliance and accounting. You save hours and just check in.
£30,000
Maximum fine for a missed safety certificate
2 years' rent
What a tenant can claim back if you're non-compliant
4×
Quarterly MTD filings a year, instead of one return
31 hrs
A month on admin, across the average landlord's portfolio
How it works
What MillOS handles for you
Connect once. MillOS runs it from there.
01
You connect once
Add your properties, drop in your certificates, link your bank read-only. Ten minutes, once.
02
MillOS reads it
It extracts every expiry, matches rent to the right flat and files each expense to the right property.
03
MillOS does the work
It books the engineer, arranges tenant access, chases late rent and reconciles the ledger — not a reminder in sight.
04
You stay ready
MillOS sends your figures to your accountant each quarter and keeps an evidence pack ready per property.
How MillOS works
One AI. Two closed loops.
Scroll to open the mill ↓
Agent 01
Certificates
Every certificate, renewed without you.
→Reads each certificate the day it lands
→Books the engineer 90 days ahead
→Arranges tenant access itself
0 missed deadlines
Gas Safety · Flat 2Renewed ✓
EICR · Flat 5Booked Thu
EPC · Flat 7Valid to 2031
Portfolio score96 / 100
Agent 02
Accounting
Your books, MTD-ready every quarter.
→Matches every rent payment to the right flat
→Files invoices and expenses as they arrive
→Sends the MTD pack to your accountant
£696 tax saved this quarter
Rent matched8 of 8 flats
Expenses filed£3,480
Q3 figuresPrepared
MTD packSent to accountant
Platform
One mill. Every feature turning.
Everything MillOS does for your portfolio, running around one engine.
Open Banking rent
Books the engineer
Live reports
Calendar invites
MTD-ready figures
Auto follow-ups
Evidence vault
WhatsApp & email
Reads certificates
Accountant pack
Expense capture
Compliance score
Tenant access
Expiry tracking
Full audit trail
Certificates
Expiry trackingReads every certificateBooks the engineerTenant accessEvidence vault
Explore →Accounting
Open Banking rentExpense captureMTD-ready figuresAccountant pack
Explore →Messages & scheduling
WhatsApp & emailCalendar invitesAutomatic follow-ups
Explore →Portfolio insight
Compliance scoreLive reportsFull audit trail
Explore →Testimonials
What UK landlords are saying
Landlords and agents love how MillOS makes a missed deadline impossible.
JW
MillOS caught two Gas Safety certs about to lapse before I'd even noticed. It has genuinely made a missed deadline impossible across my portfolio.
James Whitfield
Portfolio landlord · 34 units
PR
The compliance score per property is the first thing my team checks every morning. Onboarding a new managed property takes minutes now.
Priya Ramesh
Letting agent · Manchester
DO
Per-room rent tracking via Open Banking replaced three spreadsheets. I can see exactly which room is late the day it happens.
Daniel Okafor
HMO operator · Leeds
JW
MillOS caught two Gas Safety certs about to lapse before I'd even noticed. It has genuinely made a missed deadline impossible across my portfolio.
James Whitfield
Portfolio landlord · 34 units
PR
The compliance score per property is the first thing my team checks every morning. Onboarding a new managed property takes minutes now.
Priya Ramesh
Letting agent · Manchester
DO
Per-room rent tracking via Open Banking replaced three spreadsheets. I can see exactly which room is late the day it happens.
Daniel Okafor
HMO operator · Leeds
JW
MillOS caught two Gas Safety certs about to lapse before I'd even noticed. It has genuinely made a missed deadline impossible across my portfolio.
James Whitfield
Portfolio landlord · 34 units
PR
The compliance score per property is the first thing my team checks every morning. Onboarding a new managed property takes minutes now.
Priya Ramesh
Letting agent · Manchester
DO
Per-room rent tracking via Open Banking replaced three spreadsheets. I can see exactly which room is late the day it happens.
Daniel Okafor
HMO operator · Leeds
JW
MillOS caught two Gas Safety certs about to lapse before I'd even noticed. It has genuinely made a missed deadline impossible across my portfolio.
James Whitfield
Portfolio landlord · 34 units
PR
The compliance score per property is the first thing my team checks every morning. Onboarding a new managed property takes minutes now.
Priya Ramesh
Letting agent · Manchester
DO
Per-room rent tracking via Open Banking replaced three spreadsheets. I can see exactly which room is late the day it happens.
Daniel Okafor
HMO operator · Leeds
Architecture
Built like a mill.
Six layers under every loop MillOS runs.
Where you use itSurfaces
Web app today, phone apps next, plus WhatsApp and email.
The loopsWorkflows
Renewal and reconciliation loops that run with no setup.
ConnectionsIntegrations
Open Banking, Gmail and Outlook, Google Calendar and WhatsApp.
Rule engineCompliance
Five UK & Ireland rulebooks, so every deadline is known in advance.
MemoryContext
Every certificate, payment and conversation informs the next decision.
TrustGovernance
Every action logged. Role-based access. UK-hosted. GDPR.
Blog and articles
The latest for UK landlords
Compliance rules, tax changes and accounting playbooks — written by our UK property specialists.
complianceSmoke Alarm Regulations for UK Landlords
Where smoke alarms are required, testing rules and the 2022 update to the Smoke and Carbon Monoxide Alarm Regulations for landlords.
certificatesGas Safety Certificate (CP12): Everything UK Landlords Need to Know
The Gas Safety Certificate (CP12) is the single most important document for UK landlords. Here's who needs one, how often it renews, what happens if you miss it, and how to automate the renewal cycle.
open-bankingOpen Banking for Landlords: Why It's the New Standard
Open Banking gives UK landlords a read-only, real-time view of rent, expenses and reconciliation across every bank account. Here's how it works and why manual bank statements are finished.
iOS & Android apps — coming soon
Two loops running
you save hours, just check in
The Certificates loop books your engineers and renews every certificate. The Accounting loop reconciles the rent and prepares your quarterly figures. You just check in when it's done.
Certificates loop — books the engineer, arranges tenant access, files the certificate
Accounting loop — matches the rent, files the expenses, emails your accountant
MillOS
Friday 16 October
9:41
MillOSnow
Gas Safety booked · Flat 2
Engineer confirmed for Sat 19th, tenant notified.
MillOSnow
Rent matched · £1,250
Flat 4 paid on time. Ledger reconciled.
MillOSnow
MTD pack sent to accountant
Q3 figures prepared and emailed for review.
✓No credit card needed
✓Setup in 2 minutes
✓Cancel any time