What is the base date in a JCT subcontract?
The base date is the date your prices are fixed to, and your subcontract measures any fluctuations from it.
Updated: . By Jack Butler-Kettle, Construction Claims Consultant.
The answer
Your subcontract states it, usually in the particulars at the front. It is not the date you signed or the date you started. It is the date your tender prices are taken to reflect. If your subcontract has a JCT fluctuation option, every adjustment is measured from the base date. Under Option A that means the contributions, levies and taxes at the base date. Under Option B it means your list of basic prices at the base date. Under Option C it means the index figures for the base date. A rise before the base date is in your price. A rise after it may be recoverable, if the option covers it. Without a fluctuation option, the base date does little for your money, and a rise is usually yours unless your main contractor caused it. So check the base date before you sign. It should match the date your tender prices were set. A base date months after you priced leaves every rise in between with you, because the adjustment only starts from it. That can happen when the base date is copied from the main contract or set at the date of the order. Our Price Rise Loss Prevention service checks the base date and the fluctuation terms before you sign.
Example
Illustrative example. The scenario and figures are invented.
The facts
A drylining subcontractor priced a job in March, from board and stud quotes dated 1 March. The subcontract arrives in September with the JCT labour and materials option, Option B, and a base date of 1 September.
What happens
- The subcontractor compares the base date with the date of its supplier quotes.
- Board and stud rose 9% between March and September, worth £16,200 on the £180,000 of materials in the package.
- With a base date of 1 September, that rise would never be adjusted, because Option B only measures change from the base date.
- Before signing, the subcontractor asks for the base date to be changed to 1 March, with its March price list attached.
The rise at stake
| Item | Amount |
|---|---|
| Materials in the package | £180,000 |
| Rise from March to September | 9% |
| Rise at stake | £16,200 |
The outcome
The base date is changed to 1 March. The £16,200 rise, and any later ones, can then be recovered under Option B, subject to its notice rules.
To have the base date and the fluctuation terms checked before you sign, see our Price Rise Loss Prevention service.