Keystone Build & Design Limited
- Company number
- 16157684
- Incorporated
- 31 Dec 20241 year trading
- Registered office
- Flat 3 Blackbird Court, Brichen Grove, the Hyde, London, NW9 8SA
- Nature of business
- Construction of domestic buildings; Electrical installation; Plumbing, heat and air-conditioning installation; Painting
Keystone Build & Design Limited is a 1-year-old private limited company registered in the Hyde, company number 16157684, one of the UK's building contractors. Companies House shows its accounts as overdue: they were due on 30 September 2026.
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 Keystone Build & Design Limited is registered
The registered office is in the Hyde (NW9), in the Brent local authority area, London. Show NW9 8SA on a map.
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What happens if Keystone Build & Design Limited files late
If the accounts reach Companies House today, the late filing penalty is £150 (£300 if last year's accounts were also late). It rises at each step below.
| Companies House | Accounts delivered | Penalty |
|---|---|---|
| Up to 1 month late | 1 Oct 2026 to 31 Oct 2026 | £150 |
| 1 to 3 months late | 1 Nov 2026 to 31 Dec 2026 | £375 |
| 3 to 6 months late | 1 Jan 2027 to 31 Mar 2027 | £750 |
| More than 6 months late | From 1 Apr 2027 | £1,500 |
Penalties double if the accounts were also late the year before.
| HMRC (CT600) | From | Penalty |
|---|---|---|
| 1 day late | 1 Jan 2027 | £200 |
| 3 months late | 31 Mar 2027 | another £200 |
| 6 months late | 30 Jun 2027 | HMRC estimates the tax and adds 10% of the unpaid tax |
| 12 months late | 31 Dec 2027 | 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
- 16157684
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 31 December 2024 (1 year ago)
- Registered office
- Flat 3 Blackbird Court, Brichen Grove, the Hyde, London, NW9 8SA
- Nature of business
- Construction of domestic buildings (SIC 41202)
Electrical installation (SIC 43210)
Plumbing, heat and air-conditioning installation (SIC 43220)
Painting (SIC 43341) - Year end
- 31 December (accounting reference date)
- Accounts type
- No accounts filed yet
- Last confirmation statement
- 30 December 2025
- Previous names
- RC Desin&Build Ltd (until 6 Apr 2026)
Filing notes for building contractors
Building companies often run the Construction Industry Scheme as a contractor, a subcontractor or both. CIS deductions suffered during the year are set against the PAYE bill, and any unrecovered balance at the year end matters when the accounts are drawn up.
Similar companies
Other active building contractors.
Frequently asked questions
When are Keystone Build & Design Limited's accounts due?
Keystone Build & Design Limited's accounts were due at Companies House on 30 September 2026 and the register shows them as overdue.
When is Keystone Build & Design Limited'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 December 2025, due by 30 December 2026, and one for the period to 31 December 2025, due by 31 December 2026. Corporation tax is payable 9 months and 1 day after the end of each.
Is Keystone Build & Design Limited still trading?
Keystone Build & Design Limited 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 Keystone Build & Design Limited do?
Keystone Build & Design Limited is registered under Construction of domestic buildings (SIC 41202); Electrical installation (SIC 43210); Plumbing, heat and air-conditioning installation (SIC 43220); Painting (SIC 43341).
How old is Keystone Build & Design Limited?
Keystone Build & Design Limited was incorporated on 31 December 2024, 1 year ago.
What is the penalty if Keystone Build & Design 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 Keystone Build & Design Limited 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.