Free tool · Dates and deadlines

Payment due date calculator

Choose the contract and enter the date of the certificate or your statement. You get the date payment is due, the clause, and the day interest starts if it is late.

Calendar
Payment due under JBCC 6.2
Saturday 31 October 2026
7 calendar days from the certificate · 7 days from today

The due date falls on a Saturday; the period is in calendar days, so it does not move.

Clause
25.10
Interest runs from
Sun 1 Nov 2026
Interest
Interest from the due date at the rate in the contract data.

The edition's standard period; your contract data often changes it. Work out the interest if it is late.

Remind me when payment is due →

Indicative only. Check it against your signed contract and the published source before you rely on it.

Source: The standard payment clauses of each edition, from Sakhani's rules library. Your contract data usually sets the actual period.

Where the period runs from

JBCC and GCC count from the date the payment certificate is issued. FIDIC counts from the Engineer's receipt of your statement, and NEC from the assessment date. The result names the clause so you can check it in your contract data, which often changes the number of days.

Interest on late payment runs from the day after the due date. Take that date to the late payment interest calculator to see what is owed.

Worked example

A JBCC 2018 payment certificate is issued on Wednesday 28 October 2026. With the standard 7 calendar days, payment is due on Wednesday 4 November 2026, which is the local government elections public holiday. Interest runs from Thursday 5 November.

Questions about the payment due date calculator

My contract data says 14 days, not 7. Which applies?

Your contract data. The calculator shows the edition's standard period; Sakhani reads the period from your signed contract once it is uploaded.

Does the due date move if it lands on a holiday?

Calendar-day periods are not usually extended. The result tells you when the date falls on a weekend or holiday so you can plan for it.

What interest can I charge on late payment?

The rate in your contract data, or the prescribed rate of interest where the contract is silent. The late payment interest calculator does the sum.

Does this work for subcontracts?

Use the main contract the subcontract is back-to-back with, then check the subcontract's own payment clause: subcontracts often pay a set number of days after the main contractor is paid.

More free tools

Late payment interest calculator

Amount, due date and date paid: the interest owed per day and in total, at the prescribed rate, prime or your contract's rate.

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Retention calculator

Retention held to date against its limit, and how much comes back at practical and final completion.

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Notice deadline calculator

Pick JBCC, NEC, FIDIC or GCC and the event: the last day to notify, the clause, and who it goes to.

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