IPC — Interim Payment Certificates

The IPC is the contract's heartbeat — the monthly progress claim that turns physical work into invoiceable revenue. ORKSTRA's IPC engine handles cumulative quantities, retention math, materials-on-site, advance recovery, and the full certification chain to the client.

Overview

IPCs are generated from completed inspections plus manual claim entries. They route through the configured approval workflow ending with a client-signed certificate. The certificate is bilingual PDF (AR + EN) and feeds the invoice.

Screenshot: IPC line items with cumulative this period, previous, total claimed, retention

Key concepts

IPC. A single monthly claim — IPC-NN. Has cut-off date, BOQ revision reference, status (draft / submitted / under review / approved / certified / paid).

Cumulative quantity. Total claimed to date, including previous IPCs. The engine auto-fills from completed inspections.

This period. Difference between this IPC's cumulative and the previous IPC's cumulative.

Retention. Held-back percentage (typically 5-10%). First-half retention released at substantial completion; second-half at end of defects liability period.

Materials on site. Materials delivered but not yet installed. Claimable at a discounted rate (typically 70-80%).

Advance recovery. If the client paid an advance at contract start, each IPC recovers a slice (linear or front-loaded).

Net amount due. This-period × (1 − retention) − advance recovery + MOS adjustment.

Certificate. The signed PDF issued at client approval. Generates a downstream invoice in Finance.

Step-by-step: create an IPC

1. Project → IPC → New IPC.
2. Pick cut-off date (typically end of month) and BOQ revision.
3. The engine pre-fills cumulative quantities from completed inspections.
4. Review line by line — edit cumulative where needed (justified by site progress).
5. Add materials on site (lines, quantities, unit costs).
6. Verify retention and advance recovery math.
7. Save as draft or Submit for approval.

Step-by-step: approve an IPC

1. The IPC enters the approval workflow — typically PM → QS Manager → Commercial Director → Client.
2. Each approver reviews and signs or rejects with comments.
3. Once the client approves, ORKSTRA generates the certificate PDF (AR + EN) and the matching invoice.

Step-by-step: pay against an IPC

1. Finance → IPC → [IPC] → Mark as paid.
2. Enter payment date, amount, reference.
3. The IPC moves to Paid status.
4. Aging report and cash-flow update.

Common tasks

• Re-issue with revisions: if client rejects, edit and resubmit; the engine tracks revision count.
• Compare two IPCs: IPC → Compare for delta analysis.
• Export to Excel: for client-specific layouts.
• Multi-currency IPC: lines in different currencies are auto-converted using the rate on the cut-off date.

Troubleshooting

• "Cumulative looks wrong." — Engine uses inspection data. Check Inspections → [BOQ line] for the latest accepted inspection.
• "Retention isn't deducting." — Retention rate is configured at project level. Project → Settings → IPC → Retention rate.
• "Certificate PDF is in EN only." — User language preference. Switch to AR before generating, or use the bilingual layout.
• "Approval stuck at client step." — External approvers get a tokenized link via email. Resend from IPC → Audit → Resend client link.

Permissions reference

Permission	Who needs it
IPC_VIEW	PMs, QSes, Finance
IPC_CREATE	QSes
IPC_SUBMIT	Senior QSes
IPC_APPROVE	Approvers in the workflow
IPC_CERTIFY	Commercial Director
IPC_PAYMENT_RECORD	Finance

See also: BOQ, Variations, Approvals, Reports.