- Companies
- Civil engineering
- Norwich
- Marine and Subsea Ltd
Marine and Subsea Ltd
- Company number
- 12753154
- Incorporated
- 19 Jul 20206 years trading
- Registered office
- C/O GLX, 69-75 Thorpe Road, Norwich, Norfolk, NR1 1UA
- Nature of business
- Construction of water projects
Marine and Subsea Ltd is a 6-year-old private limited company registered in Norwich, company number 12753154, one of 105 civil engineering contractors in Norwich. Its next accounts are due at Companies House on 30 April 2027, and the CT600 for the period to 31 July 2026 is due at HMRC on 31 July 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 up £4,973 on the year before, to £5,466.
- Net assets rose in 1 of 4 year-on-year comparisons on record.
- Current assets of £29K against £23K owed within a year: 1.3 times cover.
- 1 employee on average during the year.
- Balance sheets on record for 5 years, 2021 to 2025.
Net assets by year
| Year end | Net assets | Cash | Current assets | Owed within a year | Employees |
|---|---|---|---|---|---|
| 31 Jul 2025 | £5,466 | £29K | £23K | 1 | |
| 31 Jul 2024 | £493 | £12K | £11K | 1 | |
| 31 Jul 2023 | £2,172 | £12K | £9,226 | 1 | |
| 31 Jul 2022 | £5,089 | £14K | £8,749 | 1 | |
| 31 Jul 2021 | £6,608 | £15K | £9,840 | 1 |
Who runs and owns Marine and Subsea Ltd
From the Companies House register. Individuals are shown by initials only; the full register is on Companies House.
Officer
| Name | Role | Appointed |
|---|---|---|
| M*** W*** | Director | Jul 2020 |
1 former officer
| Name | Role | Appointed | Left |
|---|---|---|---|
| L*** F*** | Director | Jul 2020 | Mar 2024 |
Person with significant control
Where Marine and Subsea Ltd is registered
The registered office is in Norwich (NR1), in the Norwich local authority area, East of England. Show NR1 1UA on a map.
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Shared registered office
89 companies on our pages use this registered office address. An address shared this widely is usually an accountant's office or a company formation agent's service address, not where the business trades from.
What happens if Marine and Subsea 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 30 April 2027.
| Companies House | Accounts delivered | Penalty |
|---|---|---|
| Up to 1 month late | 1 May 2027 to 31 May 2027 | £150 |
| 1 to 3 months late | 1 Jun 2027 to 31 Jul 2027 | £375 |
| 3 to 6 months late | 1 Aug 2027 to 31 Oct 2027 | £750 |
| More than 6 months late | From 1 Nov 2027 | £1,500 |
Penalties double if the accounts were also late the year before.
| HMRC (CT600) | From | Penalty |
|---|---|---|
| 1 day late | 1 Aug 2027 | £200 |
| 3 months late | 31 Oct 2027 | another £200 |
| 6 months late | 31 Jan 2028 | HMRC estimates the tax and adds 10% of the unpaid tax |
| 12 months late | 31 Jul 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
- 12753154
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 19 July 2020 (6 years ago)
- Registered office
- C/O GLX, 69-75 Thorpe Road, Norwich, Norfolk, NR1 1UA
- Nature of business
- Construction of water projects (SIC 42910)
- Year end
- 31 July (accounting reference date)
- Accounts type
- Micro-entity
- Last accounts made up to
- 31 July 2025
- Last confirmation statement
- 4 August 2025
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 Norwich
Other active civil engineering contractors registered in Norwich.
- Minotaur CM Ltd2022
- Mitchell Piling Ltd2015
- Monk Plant Hire Limited2003
- MS Civils Services Ltd2024
- Munday Builders Limited2005
- MW Surfacing Limited2003
- N G Bell Contractors Limited2013
- N R Asphalt Ltd2009
All civil engineering contractors in Norwich · All trades in Norwich · Civil engineering across the UK
Frequently asked questions
When are Marine and Subsea Ltd's accounts due?
Marine and Subsea Ltd's next accounts are due at Companies House by 30 April 2027 (in 199 days), covering the period to 31 July 2026.
When is Marine and Subsea Ltd's CT600 due?
The CT600 for the period to 31 July 2026 is due at HMRC by 31 July 2027, 12 months after the period end. The corporation tax itself is payable earlier, by 1 May 2027.
Is Marine and Subsea Ltd still trading?
Marine and Subsea Ltd 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 Marine and Subsea Ltd do?
Marine and Subsea Ltd is registered under Construction of water projects (SIC 42910).
How old is Marine and Subsea Ltd?
Marine and Subsea Ltd was incorporated on 19 July 2020, 6 years ago.
Who runs Marine and Subsea Ltd?
Marine and Subsea Ltd has 1 active director, the longest-serving appointed in Jul 2020. Their names and service addresses are on the Companies House register.
Who owns Marine and Subsea Ltd?
One person or company has significant control of Marine and Subsea Ltd: an individual (owns 75% or more of the shares).
What is the penalty if Marine and Subsea 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 Marine and Subsea Ltd 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.