Under a lump sum contract you agree one fixed price for a fully defined job, and that price is deemed to cover every cost. The central Manual for Procurement of Works (Ministry of Finance, updated June 2022) says no arithmetical correction or price adjustment is allowed during evaluation or execution, payment follows milestones or an activity schedule, and detailed measurement is recorded only for additions and omissions. The quantity risk is yours. That makes it the right form for work that can be fully drawn before you start, and a dangerous one where the ground or the scope is still uncertain.

In September 2026 a group of water-supply contractors went to the Kerala High Court with a simple argument. Their contracts with the Kerala Water Authority priced every item separately, so they were item rate contracts, so the payment clauses written for lump sum work could not touch them. They lost. The Division Bench held that a contract’s payment provisions “cannot be rendered otiose merely because the contract contains an item-wise BoQ with separately quoted rates.”

That is the first thing to understand about the lump sum contract. The label matters less than the payment machinery written underneath it. Read that machinery before you quote, because once you sign, it decides how and when you are paid.

What a lump sum contract is

Clause 3.2.1 of the Works Manual describes the lump sum (fixed price) contract as one in which contractors quote “a lump sum fixed price figure for completing the works in accordance with the given designs, specifications and functional requirements.” Your price is deemed to include all elements of cost.

The Manual is blunt about when it should be used: only where the work can be defined in full, and where the risk of changes in quantity or specification, and of unforeseen site conditions such as hidden foundation problems, is minimal. Its examples are repetitive residential buildings built to standard drawings, minor bridge works, chimneys, bins and silos, and overhead tanks.

Notice what is missing from that list. Earthwork in unknown strata, road widening through built-up stretches, anything where the quantity of rock or the depth of soft soil is a guess. Those are exactly the jobs where a fixed price can turn against the person who quoted it.

Lump sum contract vs item rate contract

The Works Manual sets the common types side by side in clause 3.2. The differences that touch your money are these.

Point Lump sum contract Item rate contract Percentage rate contract
What you quote One fixed price for the defined work A rate for each item in the department’s bill of quantities One percentage above or below the estimated cost
Who carries quantity risk You Mostly the department, within the agreed band The department
Measurement Only for additions and omissions Every item measured Every item measured
How payment is worked out Contract schedule, milestones or activity percentages, or full amount on completion Measured quantity times your rate, usually within plus or minus 15 per cent per item Estimated rates on measured quantities, with your percentage added or deducted
Suits Fully drawn, repetitive or standard work Most major civil works, from buildings to roads and sewer lines Small routine works and repairs priced off a schedule of rates

Source: clauses 3.2.1 to 3.2.3 of the Manual for Procurement of Works, updated June 2022. Your own tender’s general conditions can vary these terms.

The Manual calls the item rate contract “the most commonly used contract type for civil works” and says it carries the least risk of uncertainty for the parties. If you are moving from item rate jobs to your first lump sum tender, the change in risk is real. For the difference between the two measured forms, see item rate vs percentage rate tenders.

How you get paid on a lump sum contract

You are paid from time to time as per the schedule written into the contract, or the full amount on completion. The Manual suggests priced “activity schedules”, so that a payment can be released on the percentage completion of each activity, and it tells departments that billing must match the work actually done and that “the risk of front-loading” must be “strictly guarded against”.

In plain terms, do not expect to load your price into the early activities to fund the job. A department following the Manual will look for that. Plan your cash on an even schedule, and price in the gap between finishing an activity and the money arriving, which on government work is rarely short. Our piece on payment delays on government work has the realistic timelines.

There is a benefit too. Because the main scope is not measured, there is no long wait for every item to be entered and checked in the measurement book. The Manual says detailed measurements are not required “except in respect of additions and omissions”. Fewer measurements, fewer disputes over them.

Extra work: additions, omissions and the schedule of rates

A fixed price covers a fixed scope. When the department changes the drawings, the Manual allows a schedule of rates to be specified in the contract to regulate amounts added to or deducted from the fixed sum, and says payment for such additions and omissions is regulated by the prevailing schedule of rates, as agreed upon while approving the tender or the rates.

Two practical points follow. Check that the contract actually names a schedule of rates or a method for valuing changes. And get every change in writing before your machines move, the same way you would on any variation order. On a lump sum job, unrecorded extra work is simply free work.

The inclusive price trap

The Kerala High Court ruling of 23 September 2026 in Kashmirilal Construction Pvt Ltd vs Kerala Water Authority (W.A. No. 1323 of 2026) set out the principle owners most often learn the hard way. Drawing on the standard building contract texts, the Bench said that in a simple lump sum contract, the price “will be taken to include all work incidentally necessary to achieve the contractual object, however difficult and costly that might prove to be.”

Translate that to a site. If the drawings show an overhead tank and its foundation, and you meet hard rock at footing level, the extra breaker hours, the hired excavator time and the diesel are part of the price you quoted, unless the contract treats that rock as a change. The Bench noted that the rule is softened where bills of quantities prepared to a standard method are used, which is one more reason to read exactly how your tender describes each item.

The same judgment explains what a bill of quantities does in a lump sum contract. It is a device at tender stage to compute and check one fixed sum, not a promise that quantities will be re-measured. If the department hands you quantities with a lump sum tender, check them yourself. Their errors become your loss.

EPC is a lump sum contract with design added

Clause 3.2.5 of the Manual describes Engineering, Procurement and Construction contracts as assigning investigation, design and construction to the contractor “for a lump sum price determined through competitive bidding.” The Manual notes that the Cabinet Committee on Economic Affairs has recommended EPC contracts in place of item rate contracts wherever appropriate, so expect more of them.

EPC splits risk more carefully than a plain lump sum. The contractor carries soil, weather, design and construction risk, while the department keeps the risk of delay in handing over land, local approvals, environment clearances and utility shifting. If you hire machines to an EPC firm rather than bidding yourself, the pressure that structure puts on your rates is covered in working with EPC contractors.

Before you quote a lump sum

Price the quantities yourself from the drawings, item by item, even if the tender gives a figure. Visit the site and look for the hidden risks the Manual warns about: soil, water table, rock, buried services.

Read the payment schedule and work out your cash position at each stage. Find the clause for additions and omissions and the rates it points to. Check whether any price escalation clause applies, because the Manual’s plain lump sum form allows no price adjustment.

Then check time. The Manual observes that because payment on a lump sum job is not linked to time, contractors are tempted to under-resource it, and departments are told to monitor monthly progress. A late finish still attracts liquidated damages, so price enough machines to hold the programme.

The bottom line

A lump sum contract trades measurement for certainty: one price, a payment schedule, and no item-by-item measurement except for changes. That certainty belongs to the department. You carry the quantity risk, the ground risk and the cost of anything “incidentally necessary” to finish the job, and the Kerala High Court has just reminded contractors that the payment clauses, not the name on the contract, decide what they are paid.

Quote lump sum work only where the drawings are complete and the ground is known, and build the rate from your own quantities. Current public works with their contract type stated are listed on the tenders and work opportunities desk, and if the job needs another machine, compare equipment finance options before you commit to the price.

Rates, schemes, specifications and prices change. Confirm current terms with the OEM, dealer, bank or insurer before deciding. Contract types and payment terms are set by each tender’s general and special conditions, which can depart from the Works Manual; read your contract in full and take professional advice before quoting. The Manual for Procurement of Works is published by the Department of Expenditure.