An IPC (Interim Payment Certificate) is your running monthly bill; the final bill is the one that settles the whole account. Both are about the same money - the difference is when, how much, and what is left to resolve.
Every rupee you are owed passes through the same account twice - once in the running bills, once in the final settlement. Understanding the two is the difference between getting paid monthly and getting paid in full.
The Interim Payment Certificate is issued periodically (usually monthly) by the Engineer under the contract. It certifies the value of work measured and done up to that date, minus deductions. It is your cash flow during the job - it is not a final acceptance of the quantities or rates.
The final bill (final account / final statement) is submitted when the works are complete (and often again at the end of the defects liability period). It settles the entire contract: final re-measured quantities, all variations, escalation, claims, and the release of retention money. After the final bill is certified, the account is closed - so anything omitted here is effectively lost.
| Item | IPC (running bill) | Final bill |
|---|---|---|
| When | Monthly / periodic during the work | At completion; finalised after defects period |
| Basis | Work measured to date × contract rates | Final re-measured quantities + all adjustments |
| Retention | Deducted (typically 5-10%) each IPC | Released in stages at completion and after defects |
| Variations & escalation | Included as instructed/priced to date | Finalised and closed, nothing left open |
| Status | Interim - can be revised on later measurement | Final - closes the account |
IPC #5: measured work to date Rs 15,000,000; minus 5% retention (Rs 750,000), minus material advance recovery (Rs 500,000), minus prior IPCs (Rs 11,500,000) → net payable Rs 2,250,000.
Final bill: total final measured value Rs 48,200,000, plus approved variations Rs 3,100,000, plus escalation Rs 1,400,000 → gross Rs 52,700,000; minus all IPCs already paid and the balance of retention held for the defects period → final amount due at completion, with the retained balance released after the defects liability period ends.
Payment certification follows FIDIC Sub-Clause 14 (Contract Price and Payments) - 14.3 for applications, 14.6 for the IPC, 14.11 for the final statement. Pakistani public contracts and PEC forms follow the same structure. The contract sets the retention percentages and release milestones - read them before signing the final bill.
Common questions about billing cycles in Pakistan.
Retention is a percentage (commonly 5-10%) held back from each IPC as security against defects. Under FIDIC-style contracts, half is released on the issue of the taking-over certificate and the remainder at the end of the defects liability period, once the works are finally certified.
Yes. An IPC certifies work to a date; later measurement can correct it. The final account is where all interim figures are reconciled, so an over- or under-certified IPC is normally adjusted in the final bill.
Under FIDIC 14.11 the contractor submits the final statement (and a discharge) within 56 days after the taking-over certificate. Your own contract sets the period - miss it and the entitlement can be lost, so calendar it from completion.
Related: escalation calculation · contractor billing & IPC service · running bill template · more in the knowledge base.
Struc-Arch prepares running bills, final accounts and bill reconciliation for contractors and clients.
