Subcontracting and Job Work in Indian Manufacturing: Tracking Material You Do Not Hold

Material outside your gate is not outside your books

Plating, heat treatment, machining, stitching, painting, packing and assembly are routinely outsourced. The material may spend weeks at a job worker, move directly from a supplier to that job worker, pass to a second processor, or ship to a customer without returning to the principal's factory.

The common spreadsheet says “sent 1,000 pieces”. It rarely answers which batch, which challan balance, how many were processed, rejected, scrapped, passed onward, due back or consumed against which production order.

Under GST, that gap is not merely operational. Section 19 of the CGST Act addresses input tax credit for inputs and capital goods sent for job work, including direct delivery to the job worker. Section 143 and related rules establish conditions, movement documentation and time consequences. CBIC guidance emphasises that responsibility for proper accounts of inputs and capital goods lies with the principal.

This article describes system controls, not transaction-specific tax advice. GST procedures, forms, deadlines, exceptions and valuation should be confirmed against current law and professional advice.

Separate ownership, custody and processing state

Three questions must remain independent:

1. Who owns the material? Usually the principal in a job-work flow.
2. Who physically holds it? Supplier, transporter, first job worker, second job worker or principal.
3. What state is it in? Raw, issued, in transit, received, under processing, processed, rejected, scrap or dispatched onward.

Do not transfer ownership in the ERP merely to move quantity to a job-worker location. Create non-own inventory locations or custody dimensions that keep the value in the principal's books while exposing physical possession.

A minimum record needs:

• principal GSTIN and business location;
• job-worker identity, GSTIN where applicable and premises;
• item, description and unit;
• batch, serial, heat or lot where relevant;
• principal-owned quantity and value;
• challan number and date;
• dispatch and receipt dates;
• production or customer order;
• operation or process requested;
• expected yield and return date;
• GST timeline date and alert;
• current custodian and physical location;
• further-job-worker chain;
• processed, returned, rejected, scrap and outstanding quantity.

Model job work as an outside operation

Do not treat the job worker as a normal material supplier if the principal provides the inputs. The purchase is processing service; the material remains principal-owned.

In the routing, define an outside operation with:

• process specification and acceptance criteria;
• approved job workers and capacity;
• expected turnaround;
• input and output item relationship;
• normal yield, process loss and recoverable scrap;
• service unit and rate;
• inspection requirement;
• packing and transport responsibility;
• required documents;
• whether direct onward movement is allowed.

The production order reserves material and creates the outside-processing requirement. A purchase order or service order authorises the job-worker charge. The challan controls material movement. Receipt records physical return or onward confirmation. The supplier invoice records the service cost. Those are linked documents, not one transaction.

The challan is an inventory-control document

CBIC's job-work rules state that inputs or capital goods sent to a job worker, including direct dispatch, are covered by a challan issued by the principal with prescribed details. Configure a controlled sequence and capture the applicable data.

Operationally, the challan should identify:

• principal and consignee;
• challan number and date;
• item description, classification where required, quantity and unit;
• taxable or reference value and tax information as applicable;
• transport and delivery details;
• purpose and requested process;
• source production order and operation;
• expected return or onward path;
• parent challan for partial or further movement.

Do not allow quantity on child movements to exceed the parent balance. Preserve cancelled challans with reason. A dispatch should not post without the material leaving the source location, and a printed challan should not reduce stock unless dispatch is confirmed.

Direct delivery needs a three-party match

The Act permits the principal to take credit in applicable circumstances even where inputs or capital goods are sent directly to the job worker without first reaching the principal. This improves flow but creates a visibility risk: purchase, custody and production evidence begin in different organisations.

Link:

1. principal's purchase order to supplier;
2. instruction to deliver to job worker;
3. principal-issued challan;
4. supplier dispatch document;
5. job-worker receipt with quantity, condition and date;
6. supplier invoice to principal;
7. production order and outside operation.

The job-worker receipt date can affect statutory timeline monitoring. Do not default it to supplier invoice date. Capture proof from the receiving location.

Quantity and quality exceptions need ownership. If the supplier invoiced 500 kg but the job worker received 480 kg, the ERP should hold the difference in dispute or transit, not assume full custody.

Track the statutory clock by unit of movement

CBIC guidance describes one-year and three-year periods for inputs and capital goods respectively under the job-work provisions, subject to the law's conditions and exceptions. Failure to return or otherwise supply within the applicable period can trigger deemed-supply consequences from the original movement date.

The system should calculate due dates from the legally relevant event and item type, with configurable rules rather than a hard-coded generic alarm. Track each challan line and partial balance.

Use alert stages:

• normal;
• approaching internal threshold;
• action required;
• management escalation;
• tax review before statutory deadline;
• overdue and under formal resolution.

An aggregate “material at vendors” age is insufficient. One challan can contain inputs and capital goods with different rules; partial returns can leave a small but material balance.

Assign the alert to operations, procurement and tax. Operations confirms physical status, procurement coordinates the job worker, and tax determines the required treatment. Software should not decide legal consequence from age alone.

Further job work must preserve genealogy

Material may move from machining to coating to assembly without returning to the principal. Each onward movement needs the required document and a link to original custody.

Build a chain:

principal dispatch → Job Worker A receipt → processing output → onward dispatch → Job Worker B receipt → final return or supply

At every step, reconcile opening quantity, good processed quantity, process loss, scrap, rejection and closing quantity. The principal needs visibility even when Job Worker A arranges transport.

Do not create a new unrelated challan for Job Worker B. A parent-child link lets the principal trace deadline, batch, value and responsibility to the original movement.

If materials from several principal challans are combined for processing, maintain allocation rules and batch genealogy. Physical mixing may make exact unit tracing impossible; approved proportional or batch methods must still reconcile total quantity.

Material reconciliation is a mass-balance problem

For each challan or job-work batch:

quantity sent = good quantity returned or supplied + quantity at job worker + quantity in transit + approved process loss + scrap + rejected/returned material + unresolved variance

Every term must have a state and document. “Balance with vendor” should never be the plug that absorbs every difference.

Use tolerances appropriate to process. Electroplating may add weight; cutting may produce expected scrap; heat treatment should not normally change piece count. Define measurement basis and conversions.

Reconcile by both quantity and identity where required. Ten serialised tools returned cannot settle ten different serials. Batch-controlled inputs need output genealogy for quality recall and customer requirements.

Scrap belongs to the process record

Job-work scrap can be retained, returned, sold or disposed of under commercial terms and applicable tax treatment. The ERP must distinguish:

• normal process loss with no recoverable material;
• recoverable scrap owned by principal;
• scrap contractually retained or purchased by job worker;
• rejected input returned to supplier or principal;
• defective processed output awaiting disposition;
• unaccounted shortage.

Record item or scrap category, quantity, unit, origin batch, valuation, owner, physical holder and disposition. Do not net scrap silently against the service invoice. That hides yield, custody and financial evidence.

High-value scrap needs approval, weighment or count evidence, and connection to sale or return. Review actual scrap against routing standard by job worker and process.

Include tooling and capital goods

Dies, moulds, jigs, fixtures, gauges and machines sent to job workers require a separate asset or tooling subledger even where particular statutory exceptions or treatments apply. They are easy to forget because they do not move with every batch.

Track:

• asset or tool identifier;
• ownership and book value where relevant;
• serial number and condition;
• challan and dispatch date;
• custodian and location;
• permitted products and job workers;
• maintenance and calibration due dates;
• shots, cycles or usage where relevant;
• return, transfer, disposal or scrap.

A production tool at a vendor can stop customer supply if damaged or unavailable. Treat it as capacity and risk, not only compliance inventory.

Service purchasing and material custody must reconcile

The job worker may charge by piece, kilogram, batch, machine hour or operation. The service invoice should match:

• approved rate or quotation;
• production order and operation;
• accepted processed quantity;
• quality result;
• additional authorised work;
• transport or consumable terms;
• applicable GST treatment;
• debit for loss or damage where contractually agreed.

Do not approve the service invoice solely because a purchase order exists. Goods receipt for service should reflect processing accepted, not merely material received back.

Attach the charge to the production order so finished cost includes outside processing. Late invoices should enter accrual or cost-adjustment workflow under accounting policy rather than disappearing from job margin.

Quality inspection at external processing

Define whether inspection occurs at job worker, on return or both. Record specification, sample, measurement, pass, concession, rework or rejection.

If output fails, keep material in job-worker or quarantine custody until disposition. Returning rejected output to available production inventory corrupts both stock and cost.

Link nonconformance to job worker, batch, process, input material and tool. Track cost of rework, extra freight, line disruption and scrap—not just debit note value.

Supplier performance should include first-pass yield, turnaround, quantity variance, documentation, responsiveness and disruption cost. Lowest processing rate can be the most expensive source.

Physical confirmation is part of inventory control

ERP balance needs independent evidence. Establish periodic confirmation by job worker, item, challan and batch. High-value, ageing or critical material may require site verification.

Send a system-generated statement and ask the job worker to confirm or dispute quantity and condition. Reconcile differences to documents and physical count. Preserve response, evidence and resolution.

Do not wait for annual audit. Use cycle confirmation based on value, age, movement frequency, past variance and business criticality.

The confirmation should include tools and scrap as well as productive input.

Confirm dormant balances explicitly. A job worker may agree with the total quantity while disputing whether the goods remain usable, complete or assigned to the right challan. Ask for condition, batch and physical storage evidence for ageing material. Where several principals use the same processor, require segregation or another approved identification method. Record site-visit observations and photographs against the inventory record rather than storing them in an unrelated audit folder.

If a job worker does not respond, escalate by value, age and production criticality. Silence is not confirmation and should increase control risk.

A daily job-work control queue

Show:

• dispatches not acknowledged by job worker;
• direct deliveries awaiting receipt confirmation;
• jobs due back and overdue;
• challans approaching internal and statutory thresholds;
• quantity imbalance;
• further movements awaiting acknowledgement;
• quality holds and rework;
• scrap awaiting disposition;
• service receipts without invoice and invoices without accepted service;
• tooling maintenance or calibration due;
• missing documents and transport exceptions.

Every exception needs owner, next action and due date. A dashboard count without a workflow does not recover material.

Month-end and year-end controls

Reconcile:

• job-worker inventory subledger to general-ledger inventory;
• challan movements to dispatch and receipt;
• job-work quantities to production orders and WIP;
• outside-service accrual to accepted processing;
• physical confirmations to system balances;
• GST reporting data to challan register and applicable returns;
• statutory due-date report to open line balances;
• scrap and loss to approved disposition;
• inter-job-worker transfers to parent movement.

Age by original dispatch, not last spreadsheet update. Report negative balances, items at unknown location and closed production orders with material still outside.

Master-data and approval governance

Approve each job-worker location with legal name, GST details where applicable, address, processes, quality status, commercial terms and effective dates. Prevent dispatch to an inactive or unapproved location.

Control item units, process yields, service rates and routing versions. Separate permission to create challan, confirm dispatch, acknowledge receipt, adjust quantity and close variance.

Manual adjustments require reason, evidence and independent approval. Never change an original dispatch date to reset an ageing clock.

A 60-day implementation sequence

Days 1–10: inventory the truth

Collect open challans, vendor statements, spreadsheets, tools, direct deliveries and ageing material. Perform targeted physical confirmation.

Days 11–20: define the model

Set custody locations, document flow, states, statutory rules, units, reason codes and ownership.

Days 21–35: pilot one process chain

Test principal-to-worker, direct delivery, partial return, scrap, second job worker and rejected output.

Days 36–45: integrate purchasing and costing

Match processing service to accepted quantity and production order. Reconcile inventory and WIP accounts.

Days 46–60: migrate and control

Load open balances with original dates and evidence, launch exception queues, confirm balances and close duplicate trackers.

FAQ

Does material sent for job work become the job worker's inventory? It becomes the job worker's physical custody, but the principal generally retains ownership in a job-work arrangement. The ERP should preserve that distinction.

Can inputs go directly from supplier to job worker? GST provisions contemplate direct dispatch subject to conditions. Link purchase, principal challan and job-worker receipt, and confirm the relevant dates.

What if only part of a challan returns? Close only the returned quantity. Track the remaining balance, state, custodian and original timeline by line.

Should scrap be netted against the job-work bill? Not as the only record. Record quantity, ownership, disposition and value, then account for commercial settlement separately.

Is a spreadsheet challan register sufficient? It may list documents, but it rarely controls inventory, batches, production cost, further movements, physical confirmation and exceptions in one traceable flow.

Where a system helps

A manufacturing ERP can keep principal-owned stock visible across job workers, connect challans to production and GST evidence, reconcile mass balance, alert on deadlines and include outside processing in actual product cost. Mobile acknowledgement gives the principal visibility without pretending the material is in-house.

Explore OptiForge for manufacturing.

Related reading: From Job Cards to Real Costing (KB-449) and OEE Is Not the Goal (KB-452).

Sources

• CBIC, CGST Act — Sections 19 and 143
• CBIC, Conditions and restrictions for goods sent to job worker
• CBIC, Job Work under GST flyer
• CBIC Circular No. 88/07/2019-GST