- Companies
- Civil engineering
- London
- Southsea Island Rail Limited
Southsea Island Rail Limited
- Company number
- 13303987
- Incorporated
- 30 Mar 20215 years trading
- Registered office
- 167 - 169 Great Portland Street, 5TH Floor, London, W1W 5PF
- Nature of business
- Construction of railways and underground railways
Southsea Island Rail Limited is a 5-year-old private limited company registered in London, company number 13303987, one of 1,853 civil engineering contractors in London. 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 £19K (-144.6%) on the year before, to -£5,711.
- Net assets rose in 2 of 3 year-on-year comparisons on record.
- Current assets of £152 against £6,253 owed within a year: 0.0 times cover.
- 1 employee on average, down from 3 the year before.
- Balance sheets on record for 4 years, 2022 to 2025.
Net assets by year
| Year end | Net assets | Cash | Current assets | Owed within a year | Employees |
|---|---|---|---|---|---|
| 31 Mar 2025 | -£5,711 | £152 | £152 | £6,253 | 1 |
| 31 Mar 2024 | £13K | £11K | £11K | 3 | |
| 31 Mar 2023 | £12K | £24K | £24K | £0 | 3 |
| 31 Mar 2022 | £8,449 | £21K | £15K | 0 |
Where Southsea Island Rail Limited is registered
The registered office is in London (W1W), in the Westminster local authority area, London. Show W1W 5PF on a map.
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Shared registered office
1,494 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 Southsea Island Rail 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
- 13303987
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 30 March 2021 (5 years ago)
- Registered office
- 167 - 169 Great Portland Street, 5TH Floor, London, W1W 5PF
- Nature of business
- Construction of railways and underground railways (SIC 42120)
- Year end
- 31 March (accounting reference date)
- Accounts type
- Total exemption (full)
- Last accounts made up to
- 31 March 2025
- Last confirmation statement
- 9 September 2026
- Charges (mortgages)
- 0 outstanding of 1 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 London
Other active civil engineering contractors registered in London.
- Soventix Epc UK Ltd2025
- Soventix Hybrid Limited2017
- Specific Dimension (UK) Limited2026
- Speedy North Ltd2020
- Speedy Specialists Ltd2011
- Spires Construction Ltd2017
- Sporex Construction Limited2007
- Sports Surfaces Installations Limited2011
All civil engineering contractors in London · All trades in London · Civil engineering across the UK
Frequently asked questions
When are Southsea Island Rail Limited's accounts due?
Southsea Island Rail 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 Southsea Island Rail 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 Southsea Island Rail Limited still trading?
Southsea Island Rail 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 Southsea Island Rail Limited do?
Southsea Island Rail Limited is registered under Construction of railways and underground railways (SIC 42120).
How old is Southsea Island Rail Limited?
Southsea Island Rail Limited was incorporated on 30 March 2021, 5 years ago.
What is the penalty if Southsea Island Rail 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 Southsea Island Rail 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.