There is no published supply house credit request time limit for a billing error. Return windows are published, commonly 30 to 60 days. Billing disputes are not: they are governed by your credit agreement and, far more often, by ordinary practice on both sides of the counter. In practice the honor rate falls off steeply with age, and somewhere around 90 days a correction stops being a correction and becomes a negotiation about whether it happened.
That is the “90-day rule,” though nobody ever wrote it down. It marks the point where enough systems have closed over the transaction that fixing it costs your supplier real work, and the answer shifts from “sure, I’ll credit that” to “that’s already posted.”
None of this is about anyone being difficult. The person you are asking wants to help and usually can, right up until the moment the transaction leaves their reach. This post is about where that moment is, why it is there, and how to stay in front of it.
What is published, and what is not
Two different clocks run on every supply-house transaction, and contractors routinely confuse them.
| Return window | Billing dispute window | |
|---|---|---|
| What it governs | Physical goods going back | Wrong price, wrong quantity, duplicate, unagreed freight |
| Is it published? | Yes, on most distributor websites | No |
| Typical stated terms | 30 days from delivery is common; one published policy runs 60 days on-account and 30 days on cash sales | Nothing stated |
| Governed by | The distributor’s posted return policy | Your credit agreement, plus practice |
| Common exclusions | Cut wire, non-stock, special and custom order | None stated, but age is the practical filter |
The return side is genuinely documented. One distributor policy requires prior approval, goods unused and in resalable condition, with a 30-day window from delivery and a minimum 25% restocking fee. Another sets 60 days for on-account returns and 30 days for cash sales, with no credit at all on cut wire or made-to-order material. If you are sending product back, you are on that clock and it is short and it is written down. The restocking mechanics are their own subject: see what supply house restocking fees actually cost.
The billing side is where the money usually is, and it has no posted deadline. That sounds like good news. It is not, because an undefined window is not an unlimited one. It just means the limit is discretionary, and discretion tightens with age.
Why an invoice hardens as it ages
Four separate systems close over a supply-house invoice, roughly in this order. Each one that closes makes the fix more expensive for the person you are asking.
1. The open ticket, days 0 to 7. The transaction is still recent enough that the counter person or inside sales rep remembers it, the branch has the paperwork on the desk, and in many systems the invoice can simply be corrected and reissued. This is an edit, not a credit. Nothing has to be justified to anyone.
2. Your accounts payable, days 7 to 30. Once you pay it, the error is on your side of the ledger too, and getting money back requires a credit memo rather than a corrected invoice. Standard AP practice on a mismatch is to withhold payment and request a corrected invoice or a credit note before paying, which is exactly why catching it before the check goes out is worth so much. If you have not paid yet, you have leverage that disappears the moment you do.
3. Their month close, days 30 to 60. After the period closes, a credit memo is a new document posted against a closed period, and somebody with authority has to approve it. One published institutional credit memo policy shows the shape of this on the receiving side: outstanding credit balances trigger vendor contact at 45 days and go to collections at 90. Different direction, same rhythm. Forty-five and ninety days are where finance departments generally put their escalation lines.
4. Their upstream claim window, days 60 to 90 and beyond. This is the one almost no contractor knows about, and it is the real reason 90 days is where things stop.
Your supplier is chasing a clock of its own
When your supply house sells you material at a sharp price, it is often not absorbing the discount. It is claiming it back from the manufacturer under a special pricing agreement, a ship-and-debit arrangement where the distributor files a reimbursement claim with supporting documentation such as invoices and proof of delivery.
That claim has its own aging. Trade coverage of SPA governance describes distributors paying higher cost upfront and carrying real working capital strain until rebates land, with one regional distributor freeing up over $2,000,000 by addressing claims aged past 90 days. Aged claims are a known problem on their side of the counter.
The consequence for you is direct. If you ask for a price correction while the underlying claim is still live, your supplier may be able to route the adjustment upstream. If you ask after that window has shut, the credit comes straight out of branch margin. Same request, same dollar figure, completely different cost to the person deciding. That is why a fresh request gets a yes and an old one gets an explanation, and it is not stubbornness.
What to expect at each age band
Rough guide, not a policy. Your mileage varies by supplier, by rep, and by how long you have bought there.
| Age of invoice | What you are asking for | Typical reception |
|---|---|---|
| 0 to 7 days | A corrected invoice, before you pay | Routine. Often fixed at the counter without a written request. |
| 8 to 30 days | A credit memo, invoice possibly unpaid | Straightforward with a document attached. This is the sweet spot. |
| 31 to 60 days | A credit memo against a closed period | Works, but now needs a manager and a clear paper trail. |
| 61 to 90 days | A credit memo plus a justification | Mixed. Depends heavily on the relationship and the evidence. |
| Past 90 days | An exception | Uncommon. Expect a forward-looking fix instead of money back. |
The pattern most shops report is exactly this shape: recent errors get fixed as a matter of course, and it is the two-month-old ones that come back as “sorry, that’s already posted.”
What actually changes the answer, at any age
Age sets the difficulty. Evidence sets the outcome. At every band above, the requests that get honored share the same three properties.
A specific line, not a feeling. Invoice number, line number, part number, quantity, unit price charged. “My prices seem high lately” is not actionable by anyone. “Invoice #388102, line 3, part CU90-075-B10, billed $17.80” is.
A comparison the supplier can verify on their own system. Your last three purchases of the same part, with dates and their own invoice numbers. This is the single strongest attachment, and it is why building a unit price history from twelve months of invoices pays for itself the first time you use it. The rep is not taking your word for anything; they are looking up their own records.
A named dollar amount and a named ask. “Please issue an account credit of $43.20.” Not “can you look into this.” Vague asks age badly because nobody can close them.
The document beats the timeline more often than people expect. A 70-day-old duplicate with both invoice PDFs and the check number that paid the first one is easier to honor than a 20-day-old price complaint with nothing attached. For the duplicate case specifically, how a duplicate supply-house invoice gets paid twice covers what to attach.
The wording matters less than people think, but it does matter. There are ready-to-use versions in the credit request email template post.
If you are already past 90 days
You still send it. Two reasons.
First, some of it gets honored anyway, particularly duplicates, which are unambiguous and embarrassing for everyone, and short shipments where you have a signed packing slip. Documentation-heavy cases survive aging better than judgment calls.
Second, and more important: even when the money is gone, the ask changes your forward price. Reframe it.
Instead of “please credit invoice #388102,” write: “Looking back over the last six months I see this part moved from $14.20 to $17.80 across four purchases with no notice. I understand the older invoices are closed. What I want to sort out is the current price and whether there is a contract rate I should be on for this item.”
That request costs your supplier nothing historical and gets answered far more often. You have converted a dead credit into a live pricing conversation, which is worth more anyway if you buy the part every week. That conversation is the subject of negotiating with your supply house from your own numbers.
Also, log it. An old error you cannot recover is still evidence of a pattern, and patterns are what get agreements reloaded.
The habit that beats the clock
Everything above argues for one thing: check invoices on arrival rather than at month end. Not because month-end checking is lazy, but because month-end checking is structurally too late for a third of what it finds.
A workable weekly routine, roughly twenty minutes:
- Pull the week’s invoices into one place. Email folder, photos from the truck, whatever you have.
- Check only your tracked parts. Unit price against your last purchase of the same part, same unit of measure, same branch.
- Check totals math and quantities against packing slips. The two-document version of three-way matching catches most quantity errors.
- Scan for repeats. Same amount, same vendor, two invoice numbers.
- Send anything you find the same day. One line, one number, one attachment.
The individual finds are small. A $40 error is not worth an evening. The reason to do it weekly is that the small ones are the only ones you can still recover, and they compound across a year of buying.
The short version
- No supplier publishes a credit request time limit for billing errors. Return windows are published; billing windows are practice, not policy.
- Four clocks close over an invoice: the open ticket, your payment, their month close, and their upstream claim. Each one raises the cost of fixing it.
- Days 0 to 30 is where corrections are routine. Days 31 to 90 need a manager and a paper trail. Past 90 days is an exception.
- Your supplier may be able to route a fresh adjustment upstream to the manufacturer. An old one comes out of branch margin. That is the real mechanism behind the 90-day feel.
- Evidence beats timing. Invoice number, line number, part number, prior prices with their own invoice numbers, a named dollar amount.
- Past 90 days, ask for a forward price correction instead of a credit. That question still gets answered.
- Check weekly, not monthly. Recovery rate is a function of speed more than of persistence.