- Companies
- Civil engineering
- Porthmadog
- Colin Jones (Rock Engineering) Limited
Colin Jones (Rock Engineering) Limited
- Company number
- 03477488
- Incorporated
- 8 Dec 199728 years trading
- Registered office
- Unit 11, Penamser Industrial Estate, Porthmadog, Gwynedd, LL49 9NZ
- Nature of business
- Construction of other civil engineering projects n.e.c.
Colin Jones (Rock Engineering) Limited is a 28-year-old private limited company registered in Porthmadog, company number 03477488, one of the UK's civil engineering contractors. 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 £4,237 (-0.3%) on the year before, to £1.6M.
- Net assets rose in 7 of 9 year-on-year comparisons on record.
- Current assets of £918K against £381K owed within a year: 2.4 times cover.
- 16 employees on average, down from 17 the year before.
- Balance sheets on record for 10 years, 2016 to 2025.
Net assets by year
| Year end | Net assets | Cash | Current assets | Owed within a year | Employees |
|---|---|---|---|---|---|
| 31 Mar 2025 | £1.6M | £204K | £918K | £381K | 16 |
| 31 Mar 2024 | £1.7M | £462K | £1.3M | £436K | 17 |
| 31 Mar 2023 | £1.5M | £347K | £1.3M | £306K | 16 |
| 31 Mar 2022 | £1.2M | £514K | £917K | £497K | 14 |
| 31 Mar 2021 | £706K | £293K | £669K | £378K | 14 |
| 31 Mar 2020 | £727K | £425K | £681K | £343K | 15 |
| 31 Mar 2019 | £535K | £317K | £498K | £334K | 13 |
| 31 Mar 2018 | £457K | £182K | £667K | £513K | 13 |
| 31 Mar 2017 | £255K | £73K | £289K | £310K | 0 |
| 31 Mar 2016 | £243K | £101K | £305K | £334K |
Public contracts won
Colin Jones (Rock Engineering) Limited has 3 public sector contract awards on record; the ones with their own published value total £90K, from 2018 to 2026. Source: Contracts Finder and Find a Tender award notices. For 1 of them the published figure is a shared or multi-year ceiling (a framework place, a multi-supplier award, or more than a small company could hold alone), so no value is shown. These were matched by the company's exact name because the notice gave no company number.
Awards by year
Main buyers
- Cyngor Gwynedd2 awards
- Northumberland County Council1 award
| Buyer | Contract | Value | Awarded |
|---|---|---|---|
| Cyngor Gwynedd | Gwynedd and Anglesey Structures & Coastal Maintenance Framework 2026 | Ceiling, not shown | 17 Aug 2026 |
| Cyngor Gwynedd | A487 Aberaeron to Aberarth Rock Cuttings | £38K | 12 Feb 2026 |
| Northumberland County Council | NCC065 - Installation of Rockfall Protection Fence at Craster Car Park | £52K | 21 Dec 2018 |
Where Colin Jones (Rock Engineering) Limited is registered
The registered office is in Porthmadog (LL49), in the Gwynedd local authority area, Wales. Show LL49 9NZ on a map.
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What happens if Colin Jones (Rock Engineering) 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 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
- 03477488
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 8 December 1997 (28 years ago)
- Registered office
- Unit 11, Penamser Industrial Estate, Porthmadog, Gwynedd, LL49 9NZ
- Nature of business
- Construction of other civil engineering projects n.e.c. (SIC 42990)
- Year end
- 31 March (accounting reference date)
- Accounts type
- Unaudited abridged
- Last accounts made up to
- 31 March 2025
- Last confirmation statement
- 8 December 2025
- Charges (mortgages)
- 2 outstanding of 2 registered
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 Porthmadog
Other active civil engineering contractors registered in Porthmadog.
All civil engineering contractors in Porthmadog · All trades in Porthmadog · Civil engineering across the UK
Frequently asked questions
When are Colin Jones (Rock Engineering) Limited's accounts due?
Colin Jones (Rock Engineering) Limited's next accounts are due at Companies House by 31 December 2026 (in 79 days), covering the period to 31 March 2026.
When is Colin Jones (Rock Engineering) Limited'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 Colin Jones (Rock Engineering) Limited still trading?
Colin Jones (Rock Engineering) Limited 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 Colin Jones (Rock Engineering) Limited do?
Colin Jones (Rock Engineering) Limited is registered under Construction of other civil engineering projects n.e.c. (SIC 42990).
How old is Colin Jones (Rock Engineering) Limited?
Colin Jones (Rock Engineering) Limited was incorporated on 8 December 1997, 28 years ago.
Has Colin Jones (Rock Engineering) Limited won public sector contracts?
Yes. Colin Jones (Rock Engineering) Limited has 3 contract awards from public bodies on Contracts Finder and Find a Tender (those with their own published value total £90K), most recently from Cyngor Gwynedd.
What is the penalty if Colin Jones (Rock Engineering) 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 Colin Jones (Rock Engineering) Limited 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.