Late Payment Fee: What Triggers It on a Medical Supply Invoice

A late payment fee is a charge added to an invoice that is paid after its due date. In a private purchase of lab or medical supplies, the fee exists only if the buyer and seller agreed to it in writing, so the amount, the start date and any grace period are whatever those documents say. This page is general procurement information, not legal advice.

What is a late payment fee?

A late payment fee is the seller’s charge for payment received after the due date. It is usually written as a flat amount, a percentage of the overdue balance, or periodic interest, and it appears in the seller’s terms of sale, the quote or the order acknowledgement. Nothing on this page states a typical rate or a legal cap, because the rate in a private purchase is set by the contract and the limits depend on the jurisdiction.

The fee is different from the payment terms themselves. Terms such as net 30 decide when the invoice is due; the late fee decides what happens once that date passes. The net 30 terms guide covers when the 30 days start, and the credit limit guide covers what happens when an account reaches or misses its limit.

How does a late payment fee work in a medical supply purchase?

Three questions decide whether a fee is owed and how much: when the due date starts, whether the invoice is in order, and whether the amount is in dispute. The only public, rule-based example of a late-payment charge that can be read in full is the one the US federal government applies to its own purchases, so it is a useful model for what a clear rule looks like.

What starts the clock

Under the federal Prompt Payment clause (FAR 52.232-25), payment is due on the later of 30 days after the billing office receives a proper invoice or 30 days after the government accepts the goods. Interest under the implementing regulation (5 CFR 1315.10) runs from the day after the payment due date through the payment date, and is paid only after acceptance has occurred.

What a proper invoice contains

FAR 52.232-25(a)(3) lists the fields of a proper invoice: the contractor’s name and address, invoice date and number, the contract or order number with line item, a description, quantity, unit and pricing, shipping and payment terms, the payee’s name and address, a contact for defective invoices, and tax identification or electronic funds transfer details where required. An invoice missing these can make the due date arguable, so check them before you decide an invoice is late.

What stops or prevents a charge

Under 5 CFR 1315.10(c), no interest penalty is owed when payment is delayed by a dispute over the amount or over contract compliance, on advance or financing payments, on amounts temporarily withheld as the contract allows, or when an electronic transfer fails at the Federal Reserve or the vendor’s bank. A penalty under $1.00 is not paid. If a vendor’s banking information is wrong, interest does not accrue until seven days after the correct information is received.

Which documents or terms go with a late payment fee?

A fee that is not stated in writing leaves both sides guessing, and a fee stated in one document can be contradicted by another. Federal contracting regulations show the principle: 5 CFR 1315.9 requires contracts to state payment due dates and to reference the interest-penalty rules in the documentation. The same habit applies to private purchases. Ask for these before accepting terms:

• Written terms of sale that state the fee, how it is calculated and when it starts.
• The quote and the order acknowledgement, so the fee in the terms matches what was agreed at order time. The supply agreement clause checklist shows where payment clauses sit.
• The invoice itself, showing the due date, the payment terms and the order number it relates to.
• A receiving record (packing slip or delivery confirmation), which shows when the goods arrived and supports any dispute about the due date.
• The dispute procedure, if the terms include one, including whether a disputed amount can be withheld.

For charges that arise on the shipping side, see drop ship fees and terms; for a clause that gives a party time to fix a breach before consequences begin, see the dictionary entry on a cure period.

Fee set by contract versus federal interest penalty

The table compares the two sources of a late charge using only what the federal rules state. The contract column describes the general position, not any particular supplier.

Question	Private contract charge	US federal interest penalty (5 CFR 1315.10, FAR 52.232-25)
Where the rule comes from	The agreement between buyer and seller	Regulation, referenced in the contract
Does the seller have to ask?	Depends on the terms	No; paid without regard to whether the vendor requested it
When interest starts	As the terms state	The day after the payment due date
Rate	As the terms state	The rate in effect on the day after the due date
Small amounts	As the terms state	Penalties under $1.00 are not paid
Disputes	As the terms state	No penalty when payment is delayed by a dispute over amount or contract compliance

The federal rules apply only to payments by federal agencies. They do not govern a hospital, school or laboratory buying from a private supplier.

What mistakes do small buyers make with a late payment fee?

• Counting from the wrong date. The due date may run from invoice receipt, acceptance or the invoice date; the federal clause uses the later of receipt of a proper invoice and acceptance. Check which one your terms use.
• Paying an invoice that is missing required fields without asking for a corrected one, or ignoring a defective invoice until it is overdue.
• Accepting terms that appear only on the invoice. If the fee is not in the quote or order acknowledgement, ask the seller to confirm it in writing before you place the order.
• Not recording a dispute in writing. A dispute over the amount or over whether goods meet the order is what the federal rule treats as stopping the penalty; a private contract needs its own wording.
• Letting a banking or remittance error sit. The federal rule has a specific seven-day provision for corrected banking details; private terms usually do not, so correct payee details early.

Frequently asked questions

What is a late payment fee?

It is a charge added when an invoice is paid after its due date, set by the seller’s written terms in a private purchase.

How does a late payment fee work in a medical supply purchase?

The invoice has a due date set by the payment terms. If payment arrives after it, the seller applies the fee the terms describe, unless the amount is disputed or the invoice was not in order.

Which documents or terms go with a late payment fee?

The terms of sale, the quote, the order acknowledgement, the invoice and a receiving record, plus any dispute procedure.

What mistakes do small buyers make with a late payment fee?

Counting from the wrong date, paying defective invoices, accepting fee terms that appear only on the invoice, and failing to put a dispute in writing.

Sources

• 5 CFR 1315.10, Interest penalties: law.cornell.edu/cfr/text/5/1315.10 (checked 2026-11-03)
• 5 CFR 1315.9, Contract clauses: law.cornell.edu/cfr/text/5/1315.9 (checked 2026-11-03)
• FAR 52.232-25, Prompt Payment: acquisition.gov/far/52.232-25 (checked 2026-11-03)