MTD Software for CIS Subcontractors. Record. Submit. Get Paid Right.
Built for self-employed subcontractors in the construction industry. Track your gross income before CIS
deductions, log materials and expenses, invoice contractors, and file quarterly updates directly to HMRC.
CIS subcontractors are self-employed and must comply with Making Tax Digital from April 2026. RentalBux is
HMRC-recognised MTD software
that handles your digital record keeping and quarterly submissions, so you can focus on the job, not the
paperwork.
No credit card required · 30-minute setup
- HMRC-Recognised Software
- FCA Registered
- Direct HMRC Submissions
- Open Banking Integration
- Reporting & P&L
- Accountant Access
Why Subcontractors Rely On Us
Trusted by Self-Employed Professionals Across the UK
I would highly recommend Rentalbux
I chose Rentalbux for MTD as I let 3 properties jointly and wanted a software platform that could manage all this plus I am self employed. The support from Rentalbux, particularly Aayoush has been outstanding. He has coached me through set up and helped troubleshoot any problems that I encountered with professionalism and patience. I can also see that Rentalbux are continually updating the platform to respond to the needs of customers, such as adding letting agent statements which makes it much easier to record gross and net income. I would highly recommend Rentalbux particularly if you aren’t familiar with using accountancy software as the support is fantastic.
Read more →Prompt email help
Mine is a simple case - landlord, sole owner, one property. I found the software pretty straightforward, but entering quarter one after the event had me stumped. However I received a helpful email a few hours after I asked for help, which I thought excellent service.
Read more →An excellent system with excellent support
An excellent system, versatile and easy to use for any business. Excellent, top class help and support from Aayoush! Very knowledgeable, patient, efficient and professional! A refreshing change to have such a helpful person providing all the guidance and help needed! Thank you Aayoush! Thank you to all at RentalBux! Highly recommended MTD system for the self employed, small business’ and people with rental income.
Read more →Does Making Tax Digital apply to CIS subcontractors?
Yes, if your gross income is over the threshold. CIS subcontractors are self-employed. Gross means before CIS deductions and expenses. The threshold is £50,000 from 06/04/2026, £30,000 from 06/04/2027 and £20,000 from 06/04/2028.
-
In force now
From 06/04/2026
£50,000
Gross income over this in 2024/25
-
Next
From 06/04/2027
£30,000
Gross income over this in 2025/26
-
Later
From 06/04/2028
£20,000
Gross income over this in 2026/27
Worked example: a subcontractor
Illustrative · partner review- Gross payments before CIS (2024/25)
- £62,000.00
- Business expenses
- £14,000.00
- Profit
- £48,000.00
- Qualifying income (gross, before expenses)
- £62,000.00
Over £50,000: Making Tax Digital started on 06/04/2026.
Quarterly update deadlines
- 1st update · 06/04 to 05/07
- 07/08
- 2nd update · 06/04 to 05/10
- 07/11
- 3rd update · 06/04 to 05/01
- 07/02
- 4th update · 06/04 to 05/04
- 07/05
Quarterly updates are summaries, not tax returns. The 31/01 payment deadline doesn't change.
MTD software for subcontractors, whatever your trade
RentalBux is for self-employed subcontractors paid under CIS. Your trade changes. The records and quarterly updates work the same way.
A few of the people it suits:
On the build
- Bricklayers
- Plasterers
- Carpenters and joiners
- Roofers
- Groundworkers
- Scaffolders
Wiring, pipes and heating
- Electricians
- Plumbers
- Gas and heating engineers
- Air conditioning installers
Fit-out and finishing
- Painters and decorators
- Tilers
- Floor fitters
- Kitchen and bathroom fitters
Why the details matter for CIS subcontractors
Small recording mistakes show up in your quarterly updates. These four details keep yours right.
-
Two lines per invoice
CIS comes off labour, not materials. Put each on its own line, so the deduction is worked out on the right amount.
-
What you earned vs what you received
Your updates use the full invoice value. Your bank shows less after deductions. Record both, then line them up.
-
The 20% (or 30%) already paid
Contractors hold back 20% from registered subcontractors, or 30% if you are not registered. Log each amount. It counts towards your tax bill.
-
Statements that prove it
Each deduction should come with a statement from the contractor. Save them as they arrive. You will need them when the year closes.
Why RentalBux for CIS Subcontractors?
Built for busy tradespeople. Manage income, expenses, and MTD filing in one place.
Built by Accountants Who Understand Construction
RentalBux is built by UK Property Accountants, a firm managing over 1,000 landlord and sole trader tax returns every year. The team understands the realities of construction work: multiple contractors on different sites, variable pay cycles, materials you purchase yourself, and the gap between gross invoice amounts and what actually hits your bank account after CIS deductions.
Track Gross Income and CIS Deductions Separately
CIS subcontractors must report gross income on their Self Assessment, not the net amount received after deductions. RentalBux lets you record your full invoice value alongside the CIS deduction taken by the contractor, so your books always reflect what HMRC expects. When bank feeds pull in the net payment, you can reconcile it against the gross figure and the deduction statement.
Professional Invoicing for Contractors
Create and send professional invoices to contractors directly from RentalBux. Separate labour charges from materials on each invoice, which matters because CIS deductions apply only to the labour portion. Track payment status, set up recurring invoices for regular contracts, and keep a clear record of every job completed and payment received.
HMRC-Recognised Software for Making Tax Digital
RentalBux is officially listed on HMRC's MTD software. Every quarterly update you submit through RentalBux meets the latest digital reporting requirements. As a CIS subcontractor, you are classified as self-employed by HMRC, and from 6 April 2026, MTD applies if your qualifying income exceeds £50,000.
Feel the Difference RentalBux Makes
Real challenges CIS subcontractors face, and how RentalBux solves them
| Challenge | RentalBux Solution |
|---|---|
Working for multiple contractors across different sites makes it hard to track what you have invoiced, what has been deducted, and what you have actually received. |
RentalBux consolidates all contractor income into one dashboard. Record gross invoice amounts and connect your bank to see net payments arrive, giving you one clear picture ready for HMRC quarterly submissions. |
CIS deduction statements from contractors go missing or arrive late, making it difficult to reconcile your tax credits at year-end. |
Record each CIS deduction statement as you receive it. When it comes to your Self Assessment, you have a complete digital record of every deduction to claim as a tax credit. |
Materials receipts, tool purchases, and travel costs get lost between job sites, meaning you miss out on allowable tax deductions. |
Log expenses on the go from your phone. Record materials, tool purchases, PPE, site travel, and other costs so you claim every allowable deduction against your income. |
Confusing MTD rules and quarterly digital submissions create stress on top of an already demanding work schedule. |
HMRC-recognised MTD software files your quarterly updates with built-in deadline reminders. No penalty points for late submissions in the first year (2026/27), but the reminders keep you on track from day one. |
Using generic accounting software that does not understand the difference between gross income, CIS deductions, and net pay. |
RentalBux is purpose-built for self-employed individuals. Track gross income, CIS deductions, and expenses in a structure that matches how HMRC expects you to report on the SA103 self-employment pages. |
Spending evenings and weekends doing bookkeeping instead of resting after long days on site. |
RentalBux works from your phone. Log expenses on the way home from site, check your dashboard between jobs, and let the software handle the admin so your evenings stay free. |