- Companies
- Plumbers and heating engineers
- London
- Double Six Engineering Ltd
Double Six Engineering Ltd
- Company number
- 15559063
- Incorporated
- 13 Mar 20242 years trading
- Registered office
- Crown House, 27 Old Gloucester Street, London, WC1N 3AX
- Nature of business
- Plumbing, heat and air-conditioning installation
Double Six Engineering Ltd is a 2-year-old private limited company registered in London, company number 15559063, one of 2,972 plumbing and heating companies 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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Financial snapshot, 2025
From the balance sheet at 31 March 2025, as filed at Companies House.
Where Double Six Engineering Ltd is registered
The registered office is in London (WC1N), in the Camden local authority area, London. Show WC1N 3AX on a map.
Other trade companies in WC1N
- JDB Consult LtdProperty developers
- Pixie Marine LimitedMachinery repair and installation
- Old Man Edition LtdFloor and wall tilers
- Wise Choice Security LimitedMechanics and garages
- Prime Coating Services LtdMotor traders
- Strive Lands LtdProperty developers
- Statom LimitedBuilders
- Jose Galvez LtdRepair services
Shared registered office
35 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 Double Six Engineering 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 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
- 15559063
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 13 March 2024 (2 years ago)
- Registered office
- Crown House, 27 Old Gloucester Street, London, WC1N 3AX
- 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 2025
- Last confirmation statement
- 12 March 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 London
Other active plumbing and heating companies registered in London.
- Douglas Warren Mechanical Services Ltd2026
- Downey Plumbing Services Ltd2018
- Doylesmith Ltd2022
- DP Aqua Solutions Ltd2023
- DP Mechanical and Gas Services Ltd2023
- DR Heat & Gas Limited2025
- Drafoss Limited1991
- Drain Geeks Limited2017
All plumbing and heating companies in London · All trades in London · Plumbers and heating engineers across the UK
Frequently asked questions
When are Double Six Engineering Ltd's accounts due?
Double Six Engineering Ltd's next accounts are due at Companies House by 31 December 2026 (in 80 days), covering the period to 31 March 2026.
When is Double Six Engineering Ltd'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 Double Six Engineering Ltd still trading?
Double Six Engineering 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 Double Six Engineering Ltd do?
Double Six Engineering Ltd is registered under Plumbing, heat and air-conditioning installation (SIC 43220).
How old is Double Six Engineering Ltd?
Double Six Engineering Ltd was incorporated on 13 March 2024, 2 years ago.
What is the penalty if Double Six Engineering 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 Double Six Engineering 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.