- Companies
- Plumbers and heating engineers
- Brighton
- Black Knight Southern Ltd
Black Knight Southern Ltd
- Company number
- 15155792
- Incorporated
- 22 Sep 20233 years trading
- Registered office
- 144 Mackie Avenue, Brighton, East Sussex, BN1 8SB
- Nature of business
- Plumbing, heat and air-conditioning installation
Black Knight Southern Ltd is a 3-year-old private limited company registered in Brighton, company number 15155792, one of 140 plumbing and heating companies in Brighton. Its next accounts are due at Companies House on 30 June 2027, and the CT600 for the period to 30 September 2026 is due at HMRC on 30 September 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 down £16K (-64.9%) on the year before, to £8,595.
- Current assets of £10K against £13K owed within a year: 0.8 times cover.
- 1 employee on average during the year.
- Balance sheets on record for 2 years, 2024 to 2025.
Net assets by year
| Year end | Net assets | Cash | Current assets | Owed within a year | Employees |
|---|---|---|---|---|---|
| 30 Sep 2025 | £8,595 | £8,143 | £10K | £13K | 1 |
| 30 Sep 2024 | £25K | £36K | £37K | £27K | 1 |
Where Black Knight Southern Ltd is registered
The registered office is in Brighton (BN1), in the Brighton and Hove local authority area, South East. Show BN1 8SB on a map.
Other trade companies in BN1
- Appliance & Home Care LtdRepair services
- Steeleagle LtdMachinery repair and installation
- C & G Energy Solutions LimitedPlumbers and heating engineers
- Ruihe Raising Property LtdProperty developers
- Davinci Building LtdSpecialist contractors
- Almore Roofing & Guttering LtdRoofers
- Neo Av LtdMachinery repair and installation
- Akoma Homes and Commercial Cleaning LtdCleaning companies
Shared registered office
30 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 Black Knight Southern 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 30 June 2027.
| Companies House | Accounts delivered | Penalty |
|---|---|---|
| Up to 1 month late | 1 Jul 2027 to 31 Jul 2027 | £150 |
| 1 to 3 months late | 1 Aug 2027 to 30 Sep 2027 | £375 |
| 3 to 6 months late | 1 Oct 2027 to 31 Dec 2027 | £750 |
| More than 6 months late | From 1 Jan 2028 | £1,500 |
Penalties double if the accounts were also late the year before.
| HMRC (CT600) | From | Penalty |
|---|---|---|
| 1 day late | 1 Oct 2027 | £200 |
| 3 months late | 30 Dec 2027 | another £200 |
| 6 months late | 30 Mar 2028 | HMRC estimates the tax and adds 10% of the unpaid tax |
| 12 months late | 30 Sep 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
- 15155792
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 22 September 2023 (3 years ago)
- Registered office
- 144 Mackie Avenue, Brighton, East Sussex, BN1 8SB
- Nature of business
- Plumbing, heat and air-conditioning installation (SIC 43220)
- Year end
- 30 September (accounting reference date)
- Accounts type
- Total exemption (full)
- Last accounts made up to
- 30 September 2025
- Last confirmation statement
- 21 September 2025
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 Brighton
Other active plumbing and heating companies registered in Brighton.
- BLG Engineering Limited2025
- BM Gas Services Limited2019
- Boiler and Burner Services Limited2018
- Boiler Specialist KBC Ltd2024
- Brighton Boiler Care Ltd2014
- Brighton Boiler Man Ltd2021
- Brighton Cool Air Conditioning Limited2024
- Brighton Plumbing Solutions Ltd2020
All plumbing and heating companies in Brighton · All trades in Brighton · Plumbers and heating engineers across the UK
Frequently asked questions
When are Black Knight Southern Ltd's accounts due?
Black Knight Southern Ltd's next accounts are due at Companies House by 30 June 2027 (in 260 days), covering the period to 30 September 2026.
When is Black Knight Southern Ltd's CT600 due?
The CT600 for the period to 30 September 2026 is due at HMRC by 30 September 2027, 12 months after the period end. The corporation tax itself is payable earlier, by 1 July 2027.
Is Black Knight Southern Ltd still trading?
Black Knight Southern Ltd is listed as active on the Companies House register (checked 13 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 Black Knight Southern Ltd do?
Black Knight Southern Ltd is registered under Plumbing, heat and air-conditioning installation (SIC 43220).
How old is Black Knight Southern Ltd?
Black Knight Southern Ltd was incorporated on 22 September 2023, 3 years ago.
What is the penalty if Black Knight Southern 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 Black Knight Southern Ltd on Companies House for filed documents, officers and the full history.
Based on the Companies House register (snapshot 1 Oct 2026, rechecked 13 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.