- Companies
- Civil engineering
- Ferndale
- C S J Construction SW Limited
C S J Construction SW Limited
- Company number
- 16712543
- Incorporated
- 11 Sep 20251 year trading
- Registered office
- 132 East Road, Tylorstown, Ferndale, CF43 3BP
- Nature of business
- Construction of other civil engineering projects n.e.c.
C S J Construction SW Limited is a 1-year-old private limited company registered in Ferndale, company number 16712543, one of the UK's civil engineering contractors. Its next accounts are due at Companies House on 11 June 2027, and its first CT600 is due at HMRC on 10 September 2027.
Key dates
This company has not filed accounts yet. First accounts are due 21 months after incorporation, and the first period can run longer than a year.
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Where C S J Construction SW Limited is registered
The registered office is in Ferndale (CF43), in the Rhondda Cynon Taf local authority area, Wales. Show CF43 3BP on a map.
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What happens if C S J Construction SW Limited 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 11 June 2027.
| Companies House | Accounts delivered | Penalty |
|---|---|---|
| Up to 1 month late | 12 Jun 2027 to 11 Jul 2027 | £150 |
| 1 to 3 months late | 12 Jul 2027 to 11 Sep 2027 | £375 |
| 3 to 6 months late | 12 Sep 2027 to 11 Dec 2027 | £750 |
| More than 6 months late | From 12 Dec 2027 | £1,500 |
Penalties double if the accounts were also late the year before.
| HMRC (CT600) | From | Penalty |
|---|---|---|
| 1 day late | 1 Oct 2027 | £200 |
| 3 months late | 30 Dec 2027 | another £200 |
| 6 months late | 30 Mar 2028 | HMRC estimates the tax and adds 10% of the unpaid tax |
| 12 months late | 30 Sep 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
- 16712543
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 11 September 2025 (1 year ago)
- Registered office
- 132 East Road, Tylorstown, Ferndale, CF43 3BP
- Nature of business
- Construction of other civil engineering projects n.e.c. (SIC 42990)
- Year end
- 30 September (accounting reference date)
- Accounts type
- No accounts filed yet
Filing notes for civil engineering contractors
Civil engineering contractors usually carry plant and machinery, so capital allowances (the annual investment allowance and the main pool) do much of the work in the corporation tax computation.
Similar companies in Ferndale
Other active civil engineering contractors registered in Ferndale.
All civil engineering contractors in Ferndale · All trades in Ferndale · Civil engineering across the UK
Frequently asked questions
When are C S J Construction SW Limited's accounts due?
C S J Construction SW Limited's next accounts are due at Companies House by 11 June 2027 (in 241 days), covering the period to 30 September 2026.
When is C S J Construction SW Limited's CT600 due?
The first accounts cover more than 12 months, so there are two Company Tax Returns: one for the 12 months to 10 September 2026, due by 10 September 2027, and one for the period to 30 September 2026, due by 30 September 2027. Corporation tax is payable 9 months and 1 day after the end of each.
Is C S J Construction SW Limited still trading?
C S J Construction SW Limited is listed as active on the Companies House register (checked 13 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 C S J Construction SW Limited do?
C S J Construction SW Limited is registered under Construction of other civil engineering projects n.e.c. (SIC 42990).
How old is C S J Construction SW Limited?
C S J Construction SW Limited was incorporated on 11 September 2025, 1 year ago.
What is the penalty if C S J Construction SW Limited 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 C S J Construction SW Limited on Companies House for filed documents, officers and the full history.
Based on the Companies House register (snapshot 1 Oct 2026, rechecked 13 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.