Builds a gross valuation from measured-work sections, variations and materials on site, deducts retention (JCT SBC cl. 4.18), then deducts previous applications to reach the net amount due on this application.
Quick-check only. Always verify with your quantity surveyor before certifying.
VAT is not included in this valuation. Check separately whether the domestic reverse charge applies (see the VAT/DRC calculator). Statutory payment/pay-less notice deadlines (HGCRA 1996 s.110A–111) are not calculated here. Check your contract's notice periods.
Quick-check only. Always verify with your quantity surveyor before certifying.
About this interim valuation calculator
This free interim valuation calculator builds an interim payment application (or valuation) on a construction contract, the gross value of work done, less retention, less what has already been certified, to reach the net amount due this month. It is aimed at quantity surveyors, commercial managers and contractors preparing or checking applications under JCT and similar forms. Enter your measured-work sections, instructed variations and materials on site, your retention terms and previous applications, and it returns the gross valuation, the retention held, the net valuation and the amount due this application. Everything runs in your browser. Nothing is uploaded.
How the interim valuation is calculated
The gross valuation is sections total + variations total + materials on site (RICS interim valuation guidance, s.1.16). Retention is chained from the retention engine on that gross figure, never re-derived: retention = gross × retention %, capped at the contractual retention limit (JCT SBC cl. 4.18). Of the held sum, one half releases at Practical Completion and the balance after the rectification period. The net valuation is gross − retention held, and the amount due this application is net valuation − previous applications. Which can be negative if you have over-certified. VAT and the statutory payment / pay-less notice deadlines (HGCRA 1996 s.110A–111) are out of scope.
Frequently asked questions
What retention percentage and limit should I enter?
JCT’s default is 3%, though 5% is a common amendment. Enter whatever your contract particulars state. The retention limit caps the total sum that may be held: once uncapped retention (gross × %) exceeds it, the held figure is fixed at the limit and each release tranche is worked from the capped figure. The calculator flags when the cap binds.
Does this figure include VAT?
No. The valuation is net of VAT, and you should check separately whether the CIS domestic reverse charge applies to the application. It also does not track the statutory payment and pay-less notice deadlines under the Housing Grants, Construction and Regeneration Act 1996; confirm those against your contract’s notice periods.
Can the amount due come out negative?
Yes, deliberately. If previous applications exceed the current net valuation, for example after a downward revaluation, the amount due this application is negative, signalling an over-payment to reconcile rather than a sum to certify. Always confirm the figures with your quantity surveyor before certifying.