- Companies
- Electricians
- London
- Mainfix Ltd
Mainfix Ltd
- Company number
- 17469029
- Incorporated
- 19 Sep 2026
- Registered office
- 7 Hasted Road, London, SE7 8AG
- Nature of business
- Electrical installation; Plumbing, heat and air-conditioning installation
Mainfix Ltd is a newly incorporated private limited company registered in London, company number 17469029, one of 3,448 electrical contractors in London. Its next accounts are due at Companies House on 19 June 2028, and its first CT600 is due at HMRC on 18 September 2028.
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.
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Where Mainfix Ltd is registered
The registered office is in London (SE7), in the Greenwich local authority area, London. Show SE7 8AG on a map.
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What happens if Mainfix 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 19 June 2028.
| Companies House | Accounts delivered | Penalty |
|---|---|---|
| Up to 1 month late | 20 Jun 2028 to 19 Jul 2028 | £150 |
| 1 to 3 months late | 20 Jul 2028 to 19 Sep 2028 | £375 |
| 3 to 6 months late | 20 Sep 2028 to 19 Dec 2028 | £750 |
| More than 6 months late | From 20 Dec 2028 | £1,500 |
Penalties double if the accounts were also late the year before.
| HMRC (CT600) | From | Penalty |
|---|---|---|
| 1 day late | 1 Oct 2028 | £200 |
| 3 months late | 30 Dec 2028 | another £200 |
| 6 months late | 30 Mar 2029 | HMRC estimates the tax and adds 10% of the unpaid tax |
| 12 months late | 30 Sep 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
- 17469029
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 19 September 2026
- Registered office
- 7 Hasted Road, London, SE7 8AG
- Nature of business
- Electrical installation (SIC 43210)
Plumbing, heat and air-conditioning installation (SIC 43220) - Year end
- 30 September (accounting reference date)
- Accounts type
- No accounts filed yet
Filing notes for electrical contractors
Electrical contracting companies are often a director plus a van and tools. Most fall within the micro-entity rules, so the accounts filed at Companies House are short, and the CT600 carries the tax detail.
Similar companies in London
Other active electrical contractors registered in London.
- Mains Electrics Ltd2026
- Maintenance and Electrical Technicians Ltd2025
- Maintenance Property Limited2020
- Majestic Building Maintenance Ltd2020
- Major Electrical Contractors Ltd2025
- Maki Electrical Services Ltd2019
- Maksym Naumenko Services Limited2026
- Malekos Electrical Services Limited2021
All electrical contractors in London · All trades in London · Electricians across the UK
Frequently asked questions
When are Mainfix Ltd's accounts due?
Mainfix Ltd's next accounts are due at Companies House by 19 June 2028 (in 616 days), covering the period to 30 September 2027.
When is Mainfix 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 18 September 2027, due by 18 September 2028, and one for the period to 30 September 2027, due by 30 September 2028. Corporation tax is payable 9 months and 1 day after the end of each.
Is Mainfix Ltd still trading?
Mainfix 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 Mainfix Ltd do?
Mainfix Ltd is registered under Electrical installation (SIC 43210); Plumbing, heat and air-conditioning installation (SIC 43220).
How old is Mainfix Ltd?
Mainfix Ltd was incorporated on 19 September 2026, less than a year ago.
What is the penalty if Mainfix 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 Mainfix 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.