Company profile · Builders
RD Mechanical Systems Ltd
RD Mechanical Systems Ltd is a 2-year-old private limited company registered in Harrow, company number 15761776, one of 793 building contractors in Harrow. Its next accounts are due at Companies House on 31 March 2027, and the CT600 for the period to 30 June 2026 is due at HMRC on 30 June 2027.
Key dates
Worked out from the year end and filing history on the Companies House register.
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Financial snapshot, 2025
From the balance sheet at 30 June 2025, as filed at Companies House.
Where RD Mechanical Systems Ltd is registered
The registered office is in Harrow (HA2), in the Harrow local authority area, London. Show HA2 0QS on a map.
Other trade companies in HA2
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- JNJ Engineering LimitedCivil engineering
- Notting Hill Sew LtdRepair services
- Grandwellautos LtdMotor traders
- Multisteel Powdercoating LtdPainters and decorators
- Neon Systems LtdElectricians
- Firstclass Facilities LtdCleaning companies
- PMD Construct LtdBuilders
What happens if RD Mechanical Systems Ltd files late
Companies House charges an automatic penalty the day after the deadline, and it rises the longer the accounts are late. These are the dates for this company's accounts due on 31 March 2027.
| Companies House | Accounts delivered | Penalty |
|---|---|---|
| Up to 1 month late | 1 Apr 2027 to 30 Apr 2027 | £150 |
| 1 to 3 months late | 1 May 2027 to 30 Jun 2027 | £375 |
| 3 to 6 months late | 1 Jul 2027 to 30 Sep 2027 | £750 |
| More than 6 months late | From 1 Oct 2027 | £1,500 |
Penalties double if the accounts were also late the year before.
| HMRC (CT600) | From | Penalty |
|---|---|---|
| 1 day late | 1 Jul 2027 | £200 |
| 3 months late | 30 Sep 2027 | another £200 |
| 6 months late | 30 Dec 2027 | HMRC estimates the tax and adds 10% of the unpaid tax |
| 12 months late | 30 Jun 2028 | another 10% of any unpaid tax |
For returns filed on or after 1 April 2026. Late three times in a row and the £200 penalties become £1,000 each.
Company details
As held on the Companies House register.
- Company number
- 15761776
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 5 June 2024 (2 years ago)
- Registered office
- 104 Southdown Crescent, Harrow, HA2 0QS
- Nature of business
- Construction of commercial buildings (SIC 41201)
Construction of domestic buildings (SIC 41202)
Other construction installation (SIC 43290) - Year end
- 30 June (accounting reference date)
- Accounts type
- Micro-entity
- Last accounts made up to
- 30 June 2025
- Last confirmation statement
- 10 November 2025
- Previous names
- Cata Instal Ltd (until 16 Oct 2025)
Filing notes for building contractors
Building companies often run the Construction Industry Scheme as a contractor, a subcontractor or both. CIS deductions suffered during the year are set against the PAYE bill, and any unrecovered balance at the year end matters when the accounts are drawn up.
Similar companies in Harrow
Other active building contractors registered in Harrow.
- RDC Solution Ltd2025
- Reading Construction Group Ltd2026
- Refab Ltd2026
- Regency Home Maintenance Ltd2024
- Rel Construction Limited2009
- Renvic Ltd2025
- Ripple Survey Solutions Limited2025
- Riversdale Services Limited2019
All building contractors in Harrow · All trades in Harrow · Builders across the UK
Frequently asked questions
When are RD Mechanical Systems Ltd's accounts due?
RD Mechanical Systems Ltd's next accounts are due at Companies House by 31 March 2027 (in 170 days), covering the period to 30 June 2026.
When is RD Mechanical Systems Ltd's CT600 due?
The CT600 for the period to 30 June 2026 is due at HMRC by 30 June 2027, 12 months after the period end. The corporation tax itself is payable earlier, by 1 April 2027.
Is RD Mechanical Systems Ltd still trading?
RD Mechanical Systems Ltd is listed as active on the Companies House register as of 1 Oct 2026. Active means it has not been dissolved or entered insolvency; it does not show whether it is currently taking on work.
What does RD Mechanical Systems Ltd do?
RD Mechanical Systems Ltd is registered under Construction of commercial buildings (SIC 41201); Construction of domestic buildings (SIC 41202); Other construction installation (SIC 43290).
How old is RD Mechanical Systems Ltd?
RD Mechanical Systems Ltd was incorporated on 5 June 2024, 2 years ago.
What is the penalty if RD Mechanical Systems Ltd files its accounts late?
Companies House charges £150 if the accounts are up to 1 month late, £375 up to 3 months, £750 up to 6 months and £1,500 after that, doubled if the previous year's accounts were also late. HMRC charges £200 for a CT600 filed a day late and another £200 at 3 months.
Official records
View RD Mechanical Systems Ltd on Companies House for filed documents, officers and the full history.
Based on the Companies House register (snapshot 1 Oct 2026). Deadlines are worked out from the register and assume a standard accounting period; a change of year end or a short period moves them. This page is general information, not tax or accountancy advice.