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Zellarc
Muhasib — explore our flagship business management tool

Job costing and progress billing software for UAE contractors

The commercial truth of a project sits in a few numbers — budgeted, committed, claimed, certified, paid and retained. This is the system that keeps every one of them honest.

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Overview

What this is.

Most contractors do not lack data; they lack one place where it agrees. Site knows what has been built. The QS knows what has been claimed. Finance knows what has been invoiced and paid. Nobody can say, at a moment’s notice, what a job will cost to finish, how much has been certified but not yet paid, or how much retention is sitting with clients across the portfolio.

Job costing and progress billing is the workflow chain that closes that gap: costs captured against cost codes as they are committed, claims built from measured progress against the BOQ, certificates recorded as the certifier issues them, retention tracked per contract, and tax invoices raised on the right amount. This page covers that chain in detail. For the wider system — procurement, payroll, consolidated finance — see construction ERP.

What you get

Built for the specifics.

Not a generic build with your sector’s name on it — the capabilities this particular problem actually needs.

Cost codes and budgets

Each job carries a budget broken down by cost code or work breakdown structure, matching how you estimate. Revisions are versioned, so you can see the original budget, the current budget and why they differ.

Committed versus actual cost

Purchase orders and subcontracts create committed cost the moment they are approved; supplier invoices, timesheets and plant hours turn it into actual cost. The gap between the two is the exposure accounting software never shows.

Forecast to complete

Cost to date plus committed plus the estimate to finish gives a forecast final cost per cost code. Compared against contract value including approved variations, it gives a forecast margin you can review every month rather than at handover.

Claims against the BOQ

Progress is entered as quantities or percentages against BOQ lines. The claim is built cumulatively to date, less previous claims, so each period’s application is traceable back to measured work.

Interim payment certificates

The certified amount is recorded separately from the amount claimed, line by line where needed, so differences are visible and can be chased or resubmitted. Invoices follow the certificate, not the claim.

Variations

Variations move through instructed, submitted, approved and certified states. Approved variations add to the contract value; pending ones are tracked separately, so the forecast is neither optimistic nor blind to likely income.

Retention ledger

Retention is deducted on each certificate according to the contract’s percentage and any cap, held as a receivable by contract, and released against the milestones the contract specifies.

Subcontract administration

Subcontract orders, subcontractor applications, payment certificates you issue, and back-to-back retention payable — so what you owe downstream mirrors what you are owed upstream.

Claimed, certified, paid: how a progress claim should flow

A progress claim is a chain of documents, and the system should keep every link. When one is missing — a certificate never recorded, a variation priced but not approved — the commercial position silently diverges from the accounts.

1. Measure
Site or the QS records progress against BOQ lines and approved variations for the period.
2. Apply
The system builds the cumulative application to date, deducts previous applications, and produces the claim for submission.
3. Certify
When the certificate arrives, its values are entered against the application. Differences are flagged line by line for follow-up.
4. Invoice
A tax invoice is raised for the certified amount, with retention and any advance-payment recovery deducted as the contract requires.
5. Collect and retain
Payment is matched to the invoice, and retention moves into the retention ledger until its release milestone.

Retention: holding, tracking and releasing

Retention terms are set by each contract — the percentage, any cap, and when it is released. A common pattern is a partial release at completion and the balance at the end of the defects liability period, but the system should follow your contracts rather than impose a default.

Because retention is often released years after the work, it needs its own ledger with due dates and reminders. The same applies in reverse for retention you hold from subcontractors: releasing it before your own is released is a cash-flow decision that should be made deliberately, not by accident.

VAT and e-invoicing on progress invoices

Progress invoices must carry the tax invoice particulars the FTA requires, and the timing of VAT on periodic and staged payments follows specific rules. We do not hard-code a treatment: we implement what your tax adviser confirms, and keep a trail from certificate to invoice so the position can be defended.

The Ministry of Finance has announced a Peppol-based e-invoicing model run through Accredited Service Providers: a pilot from 1 July 2026, mandatory go-live from 1 January 2027 for businesses with revenue of AED 50 million or more, and from 1 July 2027 for the rest. We design invoicing so it can connect to an Accredited Service Provider rather than being rebuilt later. Confirm the current timeline and your own obligations with the Ministry of Finance or FTA, as details can change.

Off-the-shelf module or custom build?

If your claims and retention follow a conventional pattern, a construction module in an existing ERP may be enough — including Muhasib, Zellarc’s own ERP, which has construction and projects modules. We check it against a real claim and certificate from one of your jobs before recommending it.

A custom build or extension makes sense when your QS team runs a process products cannot model, when you need site capture that feeds claims directly, or when you want to keep your current accounting and add proper job costing on top.

How it fits together

The service and the sector.

The service

ERP Software Development

Custom ERP software development for UAE businesses: finance, inventory, sales and operations in one system, ready for FTA VAT and UAE e-invoicing.

The sector

Construction & Contracting

Construction margins are won and lost on cost control. The contractor who knows the real cost of a project today is the one who is still profitable at handover.

Questions

The specifics.

An interim payment certificate (IPC) is the certifier’s confirmation — usually the consultant or engineer named in the contract — of the amount due to the contractor for a period, after assessing the contractor’s application. It often differs from the amount claimed, which is why the system records claimed and certified values separately.

Retention should sit in its own ledger by contract: receivable for retention clients hold from you, payable for retention you hold from subcontractors. Each certificate adds to it; each release reduces it. Without that separation, retention disappears into general receivables and is easily forgotten.

Job costing tracks the cost side of a job — budget, committed, actual and forecast by cost code. Project accounting is broader: it also covers the revenue side, such as claims, certificates, invoices, retention and recognised revenue, so a job can be reported as a profit centre in its own right.

Yes. Approved variations are added to the contract value and can be claimed like BOQ lines; pending variations are tracked separately so they inform the forecast without inflating the contract value or the claim.

The FTA has specific rules on the date of supply for periodic and progress payments, and they should be applied with your tax adviser rather than assumed. We build the invoicing to follow the treatment your adviser confirms, with FTA-compliant tax invoice fields and an audit trail from certificate to invoice.

Yes. Subcontracts can carry their own retention terms, and the system can link subcontract packages to the main-contract work they relate to, so retention payable and its release can be aligned with retention receivable on the main contract where your subcontracts are written back to back.

Other solutions

All solutions

Need Job costing and progress billing software for UAE contractors?

Tell us what you are trying to achieve. We will scope it honestly — including telling you if the project is smaller than you think.

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