- Company number
- 12888131
- Incorporated
- 18 Sep 20206 years trading
- Registered office
- 2 Corfe Avenue, Harrow, HA2 8SZ
- Nature of business
- Construction of domestic buildings
Quantum 25 Ltd is a 6-year-old private limited company registered in Harrow, company number 12888131, one of 793 building contractors in Harrow. 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 down £27K (-67.8%) on the year before, to £13K.
- Net assets rose in 4 of 5 year-on-year comparisons on record.
- Current assets of £21K against £8,472 owed within a year: 2.5 times cover.
- 1 employee on average during the year.
- Balance sheets on record for 6 years, 2021 to 2026.
Net assets by year
| Year end | Net assets | Cash | Current assets | Owed within a year | Employees |
|---|---|---|---|---|---|
| 31 Mar 2026 | £13K | £702 | £21K | £8,472 | 1 |
| 31 Mar 2025 | £40K | £481 | £48K | £7,899 | 1 |
| 31 Mar 2024 | £8,906 | £1,253 | £14K | £4,907 | 1 |
| 31 Mar 2023 | £7,375 | £1,574 | £12K | £4,458 | 1 |
| 31 Mar 2022 | £5,338 | £115 | £8,107 | £2,769 | 1 |
| 30 Sep 2021 | -£584 | £249 | £3,401 | £3,985 | 1 |
Where Quantum 25 Ltd is registered
The registered office is in Harrow (HA2), in the Harrow local authority area, London. Show HA2 8SZ on a map.
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What happens if Quantum 25 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 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
- 12888131
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 18 September 2020 (6 years ago)
- Registered office
- 2 Corfe Avenue, Harrow, HA2 8SZ
- Nature of business
- Construction of domestic buildings (SIC 41202)
- Year end
- 31 March (accounting reference date)
- Accounts type
- Unaudited abridged
- Last accounts made up to
- 31 March 2026
- Last confirmation statement
- 17 September 2025
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 in Harrow
Other active building contractors registered in Harrow.
- Quinz Company Limited2006
- R + G Construction Ltd2002
- R H Install & Maintain Ltd2026
- R Kells Ltd2021
- R N K Construction Limited2025
- R&RR Ltd2016
- Rabadiya Construction Ltd2021
- Radhe Construction Limited2022
All building contractors in Harrow · All trades in Harrow · Builders across the UK
Frequently asked questions
When are Quantum 25 Ltd's accounts due?
Quantum 25 Ltd's next accounts are due at Companies House by 31 December 2027 (in 445 days), covering the period to 31 March 2027.
When is Quantum 25 Ltd'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 Quantum 25 Ltd still trading?
Quantum 25 Ltd is listed as active on the Companies House register (checked 12 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 Quantum 25 Ltd do?
Quantum 25 Ltd is registered under Construction of domestic buildings (SIC 41202).
How old is Quantum 25 Ltd?
Quantum 25 Ltd was incorporated on 18 September 2020, 6 years ago.
What is the penalty if Quantum 25 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 Quantum 25 Ltd on Companies House for filed documents, officers and the full history.
Based on the Companies House register (snapshot 1 Oct 2026, rechecked 12 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.