- Companies
- Plumbers and heating engineers
- Southampton
- Protheon Plumbing & Heating Ltd
Protheon Plumbing & Heating Ltd
- Company number
- 16683522
- Incorporated
- 31 Aug 20251 year trading
- Registered office
- 51 Hobb Lane, Southampton, SO30 0GG
- Nature of business
- Plumbing, heat and air-conditioning installation
Protheon Plumbing & Heating Ltd is a 1-year-old private limited company registered in Southampton, company number 16683522, one of 246 plumbing and heating companies in Southampton. Its next accounts are due at Companies House on 31 May 2027, and its first CT600 is due at HMRC on 30 August 2027.
Key dates
This company has not filed accounts yet. First accounts are due 21 months after incorporation, and the first period can run longer than a year.
Is this your company?
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Where Protheon Plumbing & Heating Ltd is registered
The registered office is in Southampton (SO30), in the Eastleigh local authority area, South East. Show SO30 0GG on a map.
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What happens if Protheon Plumbing & Heating 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
- 16683522
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 31 August 2025 (1 year ago)
- Registered office
- 51 Hobb Lane, Southampton, SO30 0GG
- Nature of business
- Plumbing, heat and air-conditioning installation (SIC 43220)
- Year end
- 31 August (accounting reference date)
- Accounts type
- No accounts filed yet
- Last confirmation statement
- 30 August 2026
- Previous names
- KPH Southern Plumbing & Heating Ltd (until 23 Sep 2026)
Filing notes for plumbing and heating companies
Plumbing and heating companies frequently work under CIS for main contractors and also directly for homeowners, so turnover can mix CIS and non-CIS income.
Similar companies in Southampton
Other active plumbing and heating companies registered in Southampton.
- Purer Air Limited2026
- R & R Plumbing Ltd2010
- R J Gale Limited2006
- R J Monk Plumbing & Heating Limited2002
- R S Mechanical & Electrical Limited2011
- R Wilson Services Limited2003
- R.O Plumbing Ltd2020
- Rab Plumbing & Heating Services Ltd2025
All plumbing and heating companies in Southampton · All trades in Southampton · Plumbers and heating engineers across the UK
Frequently asked questions
When are Protheon Plumbing & Heating Ltd's accounts due?
Protheon Plumbing & Heating 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 Protheon Plumbing & Heating Ltd's CT600 due?
The first accounts cover more than 12 months, so there are two Company Tax Returns: one for the 12 months to 30 August 2026, due by 30 August 2027, and one for the period to 31 August 2026, due by 31 August 2027. Corporation tax is payable 9 months and 1 day after the end of each.
Is Protheon Plumbing & Heating Ltd still trading?
Protheon Plumbing & Heating 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 Protheon Plumbing & Heating Ltd do?
Protheon Plumbing & Heating Ltd is registered under Plumbing, heat and air-conditioning installation (SIC 43220).
How old is Protheon Plumbing & Heating Ltd?
Protheon Plumbing & Heating Ltd was incorporated on 31 August 2025, 1 year ago.
What is the penalty if Protheon Plumbing & Heating 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 Protheon Plumbing & Heating 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.