- Companies
- Civil engineering
- St Asaph
- GW Marine Systems Limited
GW Marine Systems Limited
- Company number
- 04252620
- Incorporated
- 16 Jul 200125 years trading
- Registered office
- c/o G W Marine Systems Ltd, Cornel Bach, Lower Denbigh RD, St Asaph, Denbighshire, LL17 0EL
- Nature of business
- Construction of water projects
GW Marine Systems Limited is a 25-year-old private limited company registered in St Asaph, company number 04252620, one of 18 civil engineering contractors in St Asaph. Its next accounts are due at Companies House on 30 September 2027, and the CT600 for the period to 31 December 2026 is due at HMRC on 31 December 2027.
Key dates
Worked out from the year end and filing history on the Companies House register.
Is this your company?
File the accounts to Companies House and the CT600 to HMRC yourself with A.X.E.L Filing. One set of questions, both filings, £49 flat. No accountant, no subscription.
File for GW Marine Systems LimitedOr get a reminder before each deadline
Free. We email you 60, 30, 14, 7 and 1 days before the accounts, CT600 and confirmation statement are due. Unsubscribe in one click.
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 £35K (-2.4%) on the year before, to £1.4M.
- Net assets rose in 5 of 8 year-on-year comparisons on record.
- Current assets of £725K against £47K owed within a year: more than 10 times cover.
- 2 employees on average during the year.
- 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 Dec 2025 | £1.4M | £725K | £47K | 2 | |
| 31 Dec 2024 | £1.5M | £798K | £54K | 2 | |
| 31 Dec 2023 | £1.5M | £182K | 2 | ||
| 31 Dec 2022 | £1.2M | £35K | 2 | ||
| 31 Dec 2021 | £1.3M | £121K | 0 | ||
| 31 Dec 2020 | £1.2M | £54K | 2 | ||
| 31 Dec 2019 | £1.2M | £97K | |||
| 31 Dec 2018 | £1.1M | £102K | |||
| 31 Dec 2017 | £1M | £72K |
Public contracts won
GW Marine Systems Limited has 4 public sector contract awards on record; the ones with their own published value total £93K, from 2017 to 2026. Source: Contracts Finder and Find a Tender award notices. For 2 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. 2 of these were matched by the company's exact name because the notice gave no company number.
Awards by year
Main buyers
- Worcestershire County Council2 awards
- North Yorkshire County Council2 awards
| Buyer | Contract | Value | Awarded |
|---|---|---|---|
| Worcestershire County Council | Underwater Inspections of Highways Structures 2026-2027 | £50K | 24 Apr 2026 |
| North Yorkshire County Council | Diving Framework 2021-2025 | Ceiling, not shown | 20 Aug 2021 |
| Worcestershire County Council | Diving Inspections of Highway Structures | Ceiling, not shown | 22 Apr 2019 |
| North Yorkshire County Council | Diving Inspections 2017-2021 | £43K | 1 Nov 2017 |
Where GW Marine Systems Limited is registered
The registered office is in St Asaph (LL17), in the Denbighshire local authority area, Wales. Show LL17 0EL on a map.
Other trade companies in LL17
- Neil's Wheels Tyre Services LtdMechanics and garages
- Baxter H&S LtdCivil engineering
- Corefortress Data Ltd.Civil engineering
- SSX Construction LtdBuilders
- Rotorix LtdCleaning companies
- Gwyn Evans CVR LimitedMechanics and garages
- Spencer Civils LimitedCivil engineering
- Optimal Home Clean LtdCleaning companies
What happens if GW Marine Systems 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 30 September 2027.
| Companies House | Accounts delivered | Penalty |
|---|---|---|
| Up to 1 month late | 1 Oct 2027 to 31 Oct 2027 | £150 |
| 1 to 3 months late | 1 Nov 2027 to 31 Dec 2027 | £375 |
| 3 to 6 months late | 1 Jan 2028 to 31 Mar 2028 | £750 |
| More than 6 months late | From 1 Apr 2028 | £1,500 |
Penalties double if the accounts were also late the year before.
| HMRC (CT600) | From | Penalty |
|---|---|---|
| 1 day late | 1 Jan 2028 | £200 |
| 3 months late | 31 Mar 2028 | another £200 |
| 6 months late | 30 Jun 2028 | HMRC estimates the tax and adds 10% of the unpaid tax |
| 12 months late | 31 Dec 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
- 04252620
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 16 July 2001 (25 years ago)
- Registered office
- c/o G W Marine Systems Ltd, Cornel Bach, Lower Denbigh RD, St Asaph, Denbighshire, LL17 0EL
- Nature of business
- Construction of water projects (SIC 42910)
- Year end
- 31 December (accounting reference date)
- Accounts type
- Micro-entity
- Last accounts made up to
- 31 December 2025
- Last confirmation statement
- 30 September 2025
- Charges (mortgages)
- 0 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 St Asaph
Other active civil engineering contractors registered in St Asaph.
- J C + K A Piper (Building Contractors) Limited1993
- JCM Construction Limited2007
- Naj Developments Limited2005
- NH Contracting NW Ltd2016
- Rab Renewables Ltd2026
- Russ Fabrications Ltd2002
- Sam Roberts Ltd2023
- Sean Carr Lining Technology Limited2012
All civil engineering contractors in St Asaph · All trades in St Asaph · Civil engineering across the UK
Frequently asked questions
When are GW Marine Systems Limited's accounts due?
GW Marine Systems Limited's next accounts are due at Companies House by 30 September 2027 (in 351 days), covering the period to 31 December 2026.
When is GW Marine Systems Limited's CT600 due?
The CT600 for the period to 31 December 2026 is due at HMRC by 31 December 2027, 12 months after the period end. The corporation tax itself is payable earlier, by 1 October 2027.
Is GW Marine Systems Limited still trading?
GW Marine Systems 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 GW Marine Systems Limited do?
GW Marine Systems Limited is registered under Construction of water projects (SIC 42910).
How old is GW Marine Systems Limited?
GW Marine Systems Limited was incorporated on 16 July 2001, 25 years ago.
Has GW Marine Systems Limited won public sector contracts?
Yes. GW Marine Systems Limited has 4 contract awards from public bodies on Contracts Finder and Find a Tender (those with their own published value total £93K), most recently from Worcestershire County Council.
What is the penalty if GW Marine Systems 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 GW Marine Systems 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.