- Companies
- Plumbers and heating engineers
- Caerphilly
- Castle Mechanical Services Ltd
Castle Mechanical Services Ltd
- Company number
- 10339198
- Incorporated
- 22 Aug 201610 years trading
- Registered office
- 50 Brynau Road, Caerphilly, CF83 1PG
- Nature of business
- Plumbing, heat and air-conditioning installation
Castle Mechanical Services Ltd is a 10-year-old private limited company registered in Caerphilly, company number 10339198, one of 32 plumbing and heating companies in Caerphilly. Its next accounts are due at Companies House on 31 December 2026, and the CT600 for the period to 31 March 2026 is due at HMRC on 31 March 2027.
Key dates
Worked out from the year end and filing history on the Companies House register.
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Finances
From each year's balance sheet filed at Companies House. Small companies do not have to publish turnover or profit, so these are balance sheet figures.
- Net assets down £3,275 (-79.8%) on the year before, to -£7,377.
- Net assets rose in 2 of 8 year-on-year comparisons on record.
- Current assets of £240 against £24K owed within a year: 0.0 times cover.
- No employees reported for the latest year (directors are often not counted as employees).
- Balance sheets on record for 9 years, 2017 to 2025.
Net assets by year
| Year end | Net assets | Cash | Current assets | Owed within a year | Employees |
|---|---|---|---|---|---|
| 31 Mar 2025 | -£7,377 | £240 | £24K | 0 | |
| 31 Mar 2024 | -£4,102 | £250 | £20K | 0 | |
| 31 Mar 2023 | -£78 | £275 | £19K | 1 | |
| 31 Mar 2022 | £4,857 | £7,670 | £24K | 1 | |
| 31 Mar 2021 | £22K | £19K | £21K | 1 | |
| 31 Mar 2020 | £31K | £44K | £56K | ||
| 31 Mar 2019 | £12K | £36K | £49K | ||
| 31 Mar 2018 | £1,687 | £30K | £49K | ||
| 31 Mar 2017 | £2,876 | £1,440 | £18K | £34K |
Where Castle Mechanical Services Ltd is registered
The registered office is in Caerphilly (CF83), in the Caerphilly local authority area, Wales. Show CF83 1PG on a map.
Other trade companies in CF83
- Owen PM LimitedBuilders
- Ecamscymru LtdMachinery repair and installation
- Bee Green Plumbing Solutions LtdPlumbers and heating engineers
- Tyga Constuction LimitedBuilders
- Grip Rip MX LtdMotor traders
- Da' Grave LtdRepair services
- First Class Cleaning Solutions LtdCleaning companies
- Vehicle Accident Repairs Solutions LtdMotor traders
What happens if Castle Mechanical Services 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 December 2026.
| Companies House | Accounts delivered | Penalty |
|---|---|---|
| Up to 1 month late | 1 Jan 2027 to 31 Jan 2027 | £150 |
| 1 to 3 months late | 1 Feb 2027 to 31 Mar 2027 | £375 |
| 3 to 6 months late | 1 Apr 2027 to 30 Jun 2027 | £750 |
| More than 6 months late | From 1 Jul 2027 | £1,500 |
Penalties double if the accounts were also late the year before.
| HMRC (CT600) | From | Penalty |
|---|---|---|
| 1 day late | 1 Apr 2027 | £200 |
| 3 months late | 30 Jun 2027 | another £200 |
| 6 months late | 30 Sep 2027 | HMRC estimates the tax and adds 10% of the unpaid tax |
| 12 months late | 31 Mar 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
- 10339198
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 22 August 2016 (10 years ago)
- Registered office
- 50 Brynau Road, Caerphilly, CF83 1PG
- Nature of business
- Plumbing, heat and air-conditioning installation (SIC 43220)
- Year end
- 31 March (accounting reference date)
- Accounts type
- Micro-entity
- Last accounts made up to
- 31 March 2025
- Last confirmation statement
- 21 August 2026
Filing notes for plumbing and heating companies
Plumbing and heating companies frequently work under CIS for main contractors and also directly for homeowners, so turnover can mix CIS and non-CIS income.
Similar companies in Caerphilly
Other active plumbing and heating companies registered in Caerphilly.
- Chad Greenway Heating Ltd2023
- Controlled Heating Solutions Ltd2011
- Dna Heating Limited2003
- Dominic Jones Heating Ltd2020
- Element Gas Ltd2013
- Gas Gold Limited2019
- Gasflair Wales Limited2003
- GT Heating Solutionz Ltd2018
All plumbing and heating companies in Caerphilly · All trades in Caerphilly · Plumbers and heating engineers across the UK
Frequently asked questions
When are Castle Mechanical Services Ltd's accounts due?
Castle Mechanical Services Ltd's next accounts are due at Companies House by 31 December 2026 (in 80 days), covering the period to 31 March 2026.
When is Castle Mechanical Services Ltd's CT600 due?
The CT600 for the period to 31 March 2026 is due at HMRC by 31 March 2027, 12 months after the period end. The corporation tax itself is payable earlier, by 1 January 2027.
Is Castle Mechanical Services Ltd still trading?
Castle Mechanical Services 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 Castle Mechanical Services Ltd do?
Castle Mechanical Services Ltd is registered under Plumbing, heat and air-conditioning installation (SIC 43220).
How old is Castle Mechanical Services Ltd?
Castle Mechanical Services Ltd was incorporated on 22 August 2016, 10 years ago.
What is the penalty if Castle Mechanical Services 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 Castle Mechanical Services 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.