Should materials go to Cost of Goods Sold or to Work in Progress?

While the job is open, work in progress, which is a balance sheet account. When the job closes, the accumulated work in progress moves to cost of goods sold in the same period the revenue is recognized. That is what keeps a job's costs and its revenue in the same month and the same tax year.

What if I do not know which job the materials are for?

Then it is overhead, and that is a legitimate answer. Forcing an arbitrary job tag onto a genuinely shared cost makes your job margins less accurate, not more.

Does it matter whether I paid by card, cash or on account?

Only for the credit side of the entry. The cost is recorded when you take possession of the materials, regardless of when the money actually leaves.

How to record materials bought for a specific job

Updated July 27, 20264 min readWritten by the WIPKeep team

The short answer

Materials bought for a specific job are recorded as a debit to that job's costs and a credit to however you paid. If you are job costing, the debit goes to Work in Progress for that job, so the lumber sits on your balance sheet attached to the job until the job closes and the cost is released against the revenue it earned.

Key takeaways

Tag the receipt to the job at the moment of purchase. Materials that arrive untagged almost never get tagged later.
Materials bought for a job are a job cost. Materials bought for the shop, the truck or general use are an overhead expense. They are different accounts and mixing them distorts every job margin you calculate.
Leftover material returned to your own stock is not a cost of that job anymore.
The card you paid with does not change the cost side of the entry, only the credit side.

You stop at the lumber yard on the way to the Smith deck and put $540 of framing lumber on the business debit card. This is the single most common transaction in a contracting business, and it is the one most often recorded in a way that quietly destroys your job margins.

The entry

Materials purchased for the Smith deck

Account	Debit	Credit
Work in Progress: Smith deckThe cost attaches to the job	$540.00
Business CheckingPaid by business debit card		$540.00
Total	$540.00	$540.00

Debits equal credits. The lumber is now a cost of the Smith deck specifically, not a general expense of your business.

If you paid with a business credit card, the credit side becomes the card's liability account instead. If a supplier put it on account, the credit goes to Accounts Payable and the payment is a separate entry later. The debit side does not change in any of those cases, because the cost happened when you took the lumber.

Job cost or overhead: how to tell

The test is simple. Would you have bought this if the job did not exist? If no, it is a job cost. If yes, it is overhead.

Job cost or overhead
Purchase	Which one	Why
Framing lumber for the Smith deck	Job cost	Bought for that job and consumed by it
A box of screws you keep on the truck	Overhead	Serves whatever job is next; no single job caused it
Permit fee for the Alvarez bathroom	Job cost	Job-specific and unavoidable for that job
New cordless drill	Overhead, or an asset if it is significant	It outlives the job
Dumpster rental for one demo	Job cost	Rented for that job's debris
Truck fuel for the week	Overhead	Splitting fuel across jobs costs more effort than the answer is worth

The two mistakes that ruin job margins

1. The untagged receipt

A cost that never gets tagged to a job does not vanish. It lands in your general profit and loss, where it quietly reduces the profit of the business while leaving the job looking better than it was. Do this a few times on a job and you will conclude that decks are wildly profitable and keep bidding them at a number that loses money.

2. The multi-job run

One trip, three jobs, one receipt. Split it. Most suppliers itemize enough for you to divide the total, and an approximate split across three jobs is far better than dumping the whole receipt on one of them.

Materials you bought but did not use

You over-ordered and eight sheets of plywood went back on the rack in your shop. Strictly, that plywood is no longer a cost of the Smith deck, because the Smith deck did not consume it. If the amount is meaningful, move it:

Unused material returned to stock

Account	Debit	Credit
Inventory	$310.00
Work in Progress: Smith deckRemoving the cost from the job that did not consume it		$310.00
Total	$310.00	$310.00

Debits equal credits. The Smith deck's true cost drops by $310 and the plywood is available for the next job.

If the amount is small, most one-person operations reasonably let it ride. The judgement is about materiality, and it is yours to make. Just make it consistently, because a rule you apply half the time is worse than either rule.

Frequently asked questions

Should materials go to Cost of Goods Sold or to Work in Progress?: While the job is open, work in progress, which is a balance sheet account. When the job closes, the accumulated work in progress moves to cost of goods sold in the same period the revenue is recognized. That is what keeps a job's costs and its revenue in the same month and the same tax year.
What if I do not know which job the materials are for?: Then it is overhead, and that is a legitimate answer. Forcing an arbitrary job tag onto a genuinely shared cost makes your job margins less accurate, not more.
Does it matter whether I paid by card, cash or on account?: Only for the credit side of the entry. The cost is recorded when you take possession of the materials, regardless of when the money actually leaves.