- Companies
- Installers
- Belfast
- Certainfil Cavity Insulation Limited
Certainfil Cavity Insulation Limited
- Company number
- NI603542
- Incorporated
- 21 Jun 201016 years trading
- Registered office
- 3 Fairway Gardens, Belfast, BT9 5NP
- Nature of business
- Other construction installation
Certainfil Cavity Insulation Limited is a 16-year-old private limited company registered in Belfast, company number NI603542, one of 53 installation companies (insulation, lifts, shutters and similar) in Belfast. 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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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 £20K (-5.1%) on the year before, to £371K.
- Net assets rose in 2 of 3 year-on-year comparisons on record.
- Current assets of £470K against £149K owed within a year: 3.2 times cover.
- 9 employees on average, up from 0 the year before.
- Balance sheets on record for 4 years, 2022 to 2025.
Net assets by year
| Year end | Net assets | Cash | Current assets | Owed within a year | Employees |
|---|---|---|---|---|---|
| 31 Mar 2025 | £371K | £296K | £470K | £149K | 9 |
| 31 Mar 2024 | £391K | £349K | £543K | £164K | 0 |
| 31 Mar 2023 | £331K | £498K | £172K | 9 | |
| 31 Mar 2022 | £134K | £298K | £159K | 9 |
Where Certainfil Cavity Insulation Limited is registered
The registered office is in Belfast (BT9), in the Belfast local authority area, Northern Ireland. Show BT9 5NP on a map.
Other trade companies in BT9
- Carnkilly Estates LimitedProperty developers
- Roux Flow and Co LtdPlumbers and heating engineers
- Ormeau Parkview LtdProperty developers
- ZK Auto LimitedMotor traders
- Alina Rista Motors LtdMotor traders
- Andrews Sheet Metal Works LtdPlumbers and heating engineers
- Carbtuneshop LtdMotor traders
- Red Compliance Electrical Services LimitedElectricians
What happens if Certainfil Cavity Insulation Limited 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
- NI603542
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 21 June 2010 (16 years ago)
- Registered office
- 3 Fairway Gardens, Belfast, BT9 5NP
- Nature of business
- Other construction installation (SIC 43290)
- Year end
- 31 March (accounting reference date)
- Accounts type
- Total exemption (full)
- Last accounts made up to
- 31 March 2025
- Last confirmation statement
- 21 June 2026
Filing notes for installation companies (insulation, lifts, shutters and similar)
Installation companies (insulation, lifts, shutters, solar and similar) often buy stock and equipment up front, so stock at the year end and capital allowances both affect the tax bill.
Similar companies in Belfast
Other active installation companies (insulation, lifts, shutters and similar) registered in Belfast.
- Clover Contract Solutions Ltd2019
- Construction Labour & Plant Ltd2024
- DCS Contract Services Ltd2025
- Delux Bathrooms and Tiling Solutions (NI) Limited2023
- Dornan Thermal Insulation Ltd2020
- DTM Precision Ltd2026
- Edl Property Management Limited2023
- Elmwood Protection Services Limited2025
All installation companies (insulation, lifts, shutters and similar) in Belfast · All trades in Belfast · Installers across the UK
Frequently asked questions
When are Certainfil Cavity Insulation Limited's accounts due?
Certainfil Cavity Insulation Limited's next accounts are due at Companies House by 31 December 2026 (in 79 days), covering the period to 31 March 2026.
When is Certainfil Cavity Insulation Limited'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 Certainfil Cavity Insulation Limited still trading?
Certainfil Cavity Insulation Limited 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 Certainfil Cavity Insulation Limited do?
Certainfil Cavity Insulation Limited is registered under Other construction installation (SIC 43290).
How old is Certainfil Cavity Insulation Limited?
Certainfil Cavity Insulation Limited was incorporated on 21 June 2010, 16 years ago.
What is the penalty if Certainfil Cavity Insulation 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 Certainfil Cavity Insulation Limited 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.