- Companies
- Plumbers and heating engineers
- High Wycombe
- Isotemp(Heating & Ventilating)Limited
Isotemp(Heating & Ventilating)Limited
- Company number
- 00750351
- Incorporated
- 15 Feb 196363 years trading
- Registered office
- Loudwater Mill Station Road, Loudwater, High Wycombe, Buckinghamshire, HP10 9UD
- Nature of business
- Plumbing, heat and air-conditioning installation
Isotemp(Heating & Ventilating)Limited is a 63-year-old private limited company registered in High Wycombe, company number 00750351, one of 120 plumbing and heating companies in High Wycombe. Its next accounts are due at Companies House on 31 December 2027, and the CT600 for the period to 31 March 2027 is due at HMRC on 31 March 2028.
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 £70K (+9.4%) on the year before, to £811K.
- Net assets rose in 8 of 9 year-on-year comparisons on record.
- 23 employees on average, up from 20 the year before.
- Balance sheets on record for 10 years, 2017 to 2026.
Net assets by year
| Year end | Net assets | Cash | Current assets | Owed within a year | Employees |
|---|---|---|---|---|---|
| 31 Mar 2026 | £811K | £330K | £491K | 23 | |
| 31 Mar 2025 | £741K | £424K | £300K | 20 | |
| 31 Mar 2024 | £1.4M | £755K | £1.5M | £212K | 17 |
| 31 Mar 2023 | £1.2M | £900K | £1.4M | £168K | 17 |
| 31 Mar 2022 | £1.1M | £848K | £1.3M | £251K | 18 |
| 31 Mar 2021 | £1.1M | £998K | £1.5M | £467K | 18 |
| 31 Mar 2020 | £912K | £657K | £1.2M | £325K | |
| 31 Mar 2019 | £828K | £478K | £1.1M | £312K | |
| 31 Mar 2018 | £786K | £445K | £1.2M | £430K | 19 |
| 31 Mar 2017 | £683K | £501K | £1.1M | £470K | 20 |
Who runs and owns Isotemp(Heating & Ventilating)Limited
From the Companies House register. Individuals are shown by initials only; the full register is on Companies House.
Officers (3)
| Name | Role | Appointed |
|---|---|---|
| R*** L*** | Director | Jun 2024 |
| J*** N*** | Director | Jun 2024 |
| S*** H*** | Secretary | Jan 1996 |
11 former officers
| Name | Role | Appointed | Left |
|---|---|---|---|
| B*** G*** | Secretary | Feb 1993 | |
| C*** L*** | Secretary | Feb 1993 | Jan 1996 |
| P*** B*** | Director | Jun 2024 | Apr 2025 |
| B*** G*** | Director | Feb 1993 | |
| T*** G*** | Director | Dec 1994 | Jul 2024 |
| C*** L*** | Director | Oct 1996 | |
| G*** L*** | Director | Dec 1994 | Jul 2024 |
| M*** L*** | Director | Dec 1994 | Jul 2024 |
| M*** L*** | Director | Oct 1996 | Dec 2006 |
| P*** L*** | Director | Dec 1994 | Jul 2024 |
| K*** L*** | Director | Aug 2010 |
People with significant control (2)
Charges (secured borrowing)
1 of 3 registered charges are outstanding. A charge is security a lender takes over a company's assets, typically for a loan, mortgage or asset finance.
| Lender | Status | Registered |
|---|---|---|
| Lloyds Bank PLC | Outstanding | Oct 1992 |
| Lloyds Bank Ltd | Satisfied Jan 2026 | Sep 1978 |
| A private lender | Satisfied May 2000 | Sep 1966 |
Where Isotemp(Heating & Ventilating)Limited is registered
The registered office is in High Wycombe (HP10), in the Buckinghamshire local authority area, South East. Show HP10 9UD on a map.
Other trade companies in HP10
- Range Fit Co LtdJoiners and carpenters
- Ajm Autos LimitedMotor traders
- Woodys LimitedJoiners and carpenters
- Ah Stottor Building Services LtdFinishing trades
- Bradley Evolve LimitedProperty developers
- The Warmth and Water Group LtdPlumbers and heating engineers
- Epds Home Improvement LtdBuilders
- Cleancoat Property Services LtdBuilders
What happens if Isotemp(Heating & Ventilating)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 2027.
| Companies House | Accounts delivered | Penalty |
|---|---|---|
| Up to 1 month late | 1 Jan 2028 to 31 Jan 2028 | £150 |
| 1 to 3 months late | 1 Feb 2028 to 31 Mar 2028 | £375 |
| 3 to 6 months late | 1 Apr 2028 to 30 Jun 2028 | £750 |
| More than 6 months late | From 1 Jul 2028 | £1,500 |
Penalties double if the accounts were also late the year before.
| HMRC (CT600) | From | Penalty |
|---|---|---|
| 1 day late | 1 Apr 2028 | £200 |
| 3 months late | 30 Jun 2028 | another £200 |
| 6 months late | 30 Sep 2028 | HMRC estimates the tax and adds 10% of the unpaid tax |
| 12 months late | 31 Mar 2029 | 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
- 00750351
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 15 February 1963 (63 years ago)
- Registered office
- Loudwater Mill Station Road, Loudwater, High Wycombe, Buckinghamshire, HP10 9UD
- Nature of business
- Plumbing, heat and air-conditioning installation (SIC 43220)
- Year end
- 31 March (accounting reference date)
- Accounts type
- Total exemption (full)
- Last accounts made up to
- 31 March 2026
- Last confirmation statement
- 12 January 2026
- Charges (mortgages)
- 1 outstanding of 3 registered
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 High Wycombe
Other active plumbing and heating companies registered in High Wycombe.
- Isotherm Building Services Ltd2026
- J A H Plumbing Limited2017
- J.R Services Plumbing and Heating Limited2021
- JDM Heating & Plumbing Ltd2026
- JMC Heating and Plumbing Ltd2020
- K O'Donoghue Gas Services Limited2020
- K. Ridgway Plumbing & Heating Limited2019
- KB Ventilation Limited2025
All plumbing and heating companies in High Wycombe · All trades in High Wycombe · Plumbers and heating engineers across the UK
Frequently asked questions
When are Isotemp(Heating & Ventilating)Limited's accounts due?
Isotemp(Heating & Ventilating)Limited's next accounts are due at Companies House by 31 December 2027 (in 444 days), covering the period to 31 March 2027.
When is Isotemp(Heating & Ventilating)Limited's CT600 due?
The CT600 for the period to 31 March 2027 is due at HMRC by 31 March 2028, 12 months after the period end. The corporation tax itself is payable earlier, by 1 January 2028.
Is Isotemp(Heating & Ventilating)Limited still trading?
Isotemp(Heating & Ventilating)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 Isotemp(Heating & Ventilating)Limited do?
Isotemp(Heating & Ventilating)Limited is registered under Plumbing, heat and air-conditioning installation (SIC 43220).
How old is Isotemp(Heating & Ventilating)Limited?
Isotemp(Heating & Ventilating)Limited was incorporated on 15 February 1963, 63 years ago.
Who runs Isotemp(Heating & Ventilating)Limited?
Isotemp(Heating & Ventilating)Limited has 2 active directors, the longest-serving appointed in Jun 2024. Their names and service addresses are on the Companies House register.
Who owns Isotemp(Heating & Ventilating)Limited?
2 people or companies have significant control of Isotemp(Heating & Ventilating)Limited: an individual (owns 25% to 50% of the shares); an individual (owns 25% to 50% of the shares).
What is the penalty if Isotemp(Heating & Ventilating)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 Isotemp(Heating & Ventilating)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.