- Companies
- Machinery repair and installation
- Prestonpans
- Williamson Bros Marine Ltd
Williamson Bros Marine Ltd
- Company number
- SC573415
- Incorporated
- 10 Aug 20179 years trading
- Registered office
- 3 Roberton Avenue, Tranent, Prestonpans, East Lothian, EH33 1JF
- Nature of business
- Repair and maintenance of ships and boats; Activities of other holding companies n.e.c.
Williamson Bros Marine Ltd is a 9-year-old private limited company registered in Prestonpans, company number SC573415, one of the UK's machinery repair and installation companies. Its next accounts are due at Companies House on 31 May 2027, and the CT600 for the period to 31 August 2026 is due at HMRC on 31 August 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 £17K (+40.8%) on the year before, to £58K.
- Net assets rose in 3 of 6 year-on-year comparisons on record.
- No employees reported for the latest year (directors are often not counted as employees).
- Balance sheets on record for 7 years, 2019 to 2025.
Net assets by year
| Year end | Net assets | Cash | Current assets | Owed within a year | Employees |
|---|---|---|---|---|---|
| 31 Aug 2025 | £58K | £0 | £35K | 0 | |
| 31 Aug 2024 | £41K | £500 | £37K | 0 | |
| 31 Aug 2023 | £38K | £548 | £48K | 0 | |
| 31 Aug 2022 | £65K | £61 | £59K | 0 | |
| 31 Aug 2021 | -£28K | £43 | £43 | £69K | 0 |
| 31 Aug 2020 | £56K | £10 | £10 | £70K | 0 |
| 31 Aug 2019 | £57K | £100 | £100 | £87K | 0 |
Where Williamson Bros Marine Ltd is registered
The registered office is in Prestonpans (EH33), in the East Lothian local authority area, Scotland. Show EH33 1JF on a map.
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What happens if Williamson Bros Marine 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 May 2027.
| Companies House | Accounts delivered | Penalty |
|---|---|---|
| Up to 1 month late | 1 Jun 2027 to 30 Jun 2027 | £150 |
| 1 to 3 months late | 1 Jul 2027 to 31 Aug 2027 | £375 |
| 3 to 6 months late | 1 Sep 2027 to 30 Nov 2027 | £750 |
| More than 6 months late | From 1 Dec 2027 | £1,500 |
Penalties double if the accounts were also late the year before.
| HMRC (CT600) | From | Penalty |
|---|---|---|
| 1 day late | 1 Sep 2027 | £200 |
| 3 months late | 30 Nov 2027 | another £200 |
| 6 months late | 29 Feb 2028 | HMRC estimates the tax and adds 10% of the unpaid tax |
| 12 months late | 31 Aug 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
- SC573415
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 10 August 2017 (9 years ago)
- Registered office
- 3 Roberton Avenue, Tranent, Prestonpans, East Lothian, EH33 1JF
- Nature of business
- Repair and maintenance of ships and boats (SIC 33150)
Activities of other holding companies n.e.c. (SIC 64209) - Year end
- 31 August (accounting reference date)
- Accounts type
- Micro-entity
- Last accounts made up to
- 31 August 2025
- Last confirmation statement
- 22 August 2026
Filing notes for machinery repair and installation companies
Machinery repair and installation companies often carry parts stock and specialist tools, and many work on contracts that span the year end.
Similar companies in Prestonpans
Other active machinery repair and installation companies registered in Prestonpans.
All machinery repair and installation companies in Prestonpans · All trades in Prestonpans · Machinery repair and installation across the UK
Frequently asked questions
When are Williamson Bros Marine Ltd's accounts due?
Williamson Bros Marine Ltd's next accounts are due at Companies House by 31 May 2027 (in 230 days), covering the period to 31 August 2026.
When is Williamson Bros Marine Ltd's CT600 due?
The CT600 for the period to 31 August 2026 is due at HMRC by 31 August 2027, 12 months after the period end. The corporation tax itself is payable earlier, by 1 June 2027.
Is Williamson Bros Marine Ltd still trading?
Williamson Bros Marine 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 Williamson Bros Marine Ltd do?
Williamson Bros Marine Ltd is registered under Repair and maintenance of ships and boats (SIC 33150); Activities of other holding companies n.e.c. (SIC 64209).
How old is Williamson Bros Marine Ltd?
Williamson Bros Marine Ltd was incorporated on 10 August 2017, 9 years ago.
What is the penalty if Williamson Bros Marine 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 Williamson Bros Marine 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.