- Companies
- Property developers
- London
- Proton+ Ltd
Proton+ Ltd
- Company number
- 14405952
- Incorporated
- 8 Oct 20224 years trading
- Registered office
- Flat G, 4 Dunnage Crescent, London, SE16 7FJ
- Nature of business
- Development of building projects; Electrical installation; Other specialised construction activities n.e.c.
Proton+ Ltd is a 4-year-old private limited company registered in London, company number 14405952, one of 14,100 property development companies in London. Its next accounts are due at Companies House on 31 July 2027, and the CT600 for the period to 31 October 2026 is due at HMRC on 31 October 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 £10K (+186.1%) on the year before, to £15K.
- Current assets of £24K against £11K owed within a year: 2.1 times cover.
- 2 employees on average, up from -1 the year before.
- Balance sheets on record for 3 years, 2023 to 2025.
Net assets by year
| Year end | Net assets | Cash | Current assets | Owed within a year | Employees |
|---|---|---|---|---|---|
| 31 Oct 2025 | £15K | £24K | £11K | 2 | |
| 31 Oct 2024 | £5,378 | £6,278 | £2,426 | -1 | |
| 31 Oct 2023 | £14K | £7,661 | £9,764 | -1 |
Public contracts won
Proton+ Ltd has one public sector contract award on record (2017). Source: Contracts Finder and Find a Tender award notices. For all 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.
| Buyer | Contract | Value | Awarded |
|---|---|---|---|
| Yorkshire Purchasing Organisation | The Design, Installation, Supply and Servicing of Commercial Catering Equipment | Ceiling, not shown | 13 Apr 2017 |
Where Proton+ Ltd is registered
The registered office is in London (SE16), in the Southwark local authority area, London. Show SE16 7FJ on a map.
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What happens if Proton+ 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 July 2027.
| Companies House | Accounts delivered | Penalty |
|---|---|---|
| Up to 1 month late | 1 Aug 2027 to 31 Aug 2027 | £150 |
| 1 to 3 months late | 1 Sep 2027 to 31 Oct 2027 | £375 |
| 3 to 6 months late | 1 Nov 2027 to 31 Jan 2028 | £750 |
| More than 6 months late | From 1 Feb 2028 | £1,500 |
Penalties double if the accounts were also late the year before.
| HMRC (CT600) | From | Penalty |
|---|---|---|
| 1 day late | 1 Nov 2027 | £200 |
| 3 months late | 31 Jan 2028 | another £200 |
| 6 months late | 30 Apr 2028 | HMRC estimates the tax and adds 10% of the unpaid tax |
| 12 months late | 31 Oct 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
- 14405952
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 8 October 2022 (4 years ago)
- Registered office
- Flat G, 4 Dunnage Crescent, London, SE16 7FJ
- Nature of business
- Development of building projects (SIC 41100)
Electrical installation (SIC 43210)
Other specialised construction activities n.e.c. (SIC 43999) - Year end
- 31 October (accounting reference date)
- Accounts type
- Micro-entity
- Last accounts made up to
- 31 October 2025
- Last confirmation statement
- 7 October 2025
Filing notes for property development companies
Many property development companies are single-project vehicles. Stock of land and buildings sits on the balance sheet as work in progress until sale, and a company that has finished its project may become dormant rather than close.
Similar companies in London
Other active property development companies registered in London.
- Prout Partnership Ltd2019
- Provate Limited1997
- Provent Consortium Ltd2016
- Provide Property Trading Ltd2026
- Providence Red Limited2021
- Provident Brickwork Ltd2022
- Provis Estates (Monmouth) Limited2006
- Provolve Solutions Limited2025
All property development companies in London · All trades in London · Property developers across the UK
Frequently asked questions
When are Proton+ Ltd's accounts due?
Proton+ Ltd's next accounts are due at Companies House by 31 July 2027 (in 292 days), covering the period to 31 October 2026.
When is Proton+ Ltd's CT600 due?
The CT600 for the period to 31 October 2026 is due at HMRC by 31 October 2027, 12 months after the period end. The corporation tax itself is payable earlier, by 1 August 2027.
Is Proton+ Ltd still trading?
Proton+ 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 Proton+ Ltd do?
Proton+ Ltd is registered under Development of building projects (SIC 41100); Electrical installation (SIC 43210); Other specialised construction activities n.e.c. (SIC 43999).
How old is Proton+ Ltd?
Proton+ Ltd was incorporated on 8 October 2022, 4 years ago.
Has Proton+ Ltd won public sector contracts?
Yes. Proton+ Ltd has one contract award from public bodies on Contracts Finder and Find a Tender, most recently from Yorkshire Purchasing Organisation.
What is the penalty if Proton+ 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 Proton+ 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.