While there is no universal law dictating exactly when an invoice must be sent, companies can generally wait up to two to six years to send an invoice in the US, depending on the state's statute of limitations for contract disputes. However, best practices dictate sending invoices promptly (within 30 days) to avoid client disputes and ensure cash flow.
There's no legal time limit that says you must invoice within a certain number of days (though doing it promptly is definitely best practice). So before you go spiraling into worst-case scenarios, remember: you're still entitled to be paid for the work you've done.
Stick within the legal time limit for invoicing.
Although the legal time limits for invoicing are usually forgiving, you should send invoices within 30 days to maintain a steady cash flow. Electronic signatures can help you keep track of your invoices.
The general rule is 30 days from the invoice date. However, you can discuss this with your customer and either make it shorter or longer than 30 days. Regardless of what you agree upon, the payment terms and the due date should be clearly stated on the invoice.
According to California Code of Civil Procedure § 337(1), the statute of limitations for a written contract is four years. Under § 339(1), the limit for an oral contract is two years.
On the other hand, there's usually no legal requirement that bills be sent out in a timely fashion—so businesses can absolutely bill your months or even years after the fact. If it's a medical debt, there's the added confusion of insurance coverage and the challenge of understanding the bill in the first place.
Under the Limitation Act 1980, invoices can be issued up to six years after the work was completed or the goods were delivered. While there is no legal restriction within this time frame, issuing invoices promptly is always best to avoid disputes or complications.
Under the current guidelines, users must upload invoices within 30 days from the invoice date. If you miss this window, the IRP will reject the invoice, which means it won't be considered valid for GST compliance or for claiming input tax credit.
Written Contracts: For debts involving written contracts, such as commercial agreements, promissory notes, or client service contracts, the statute of limitations extends to four years from the date of the breach.
If a customer asks for a tax invoice, you have 28 days to send it.
Manner of Issuing Invoice
The invoice shall be prepared in triplicate, in case of supply of goods, in the following manner: (a) The original copy being marked as ORIGINAL FOR RECIPIENT; (b) The duplicate copy being marked as DUPLICATE FOR TRANSPORTER; and (c) The triplicate copy being marked as TRIPLICATE FOR SUPPLIER.
30+ days late
If your client hasn't made payment (or meaningful contact) within 30 days of the invoice becoming due, it may be time to issue a letter before action (LBA), or to pass over the matter to a debt collection agency. An LBA gives your client formal notice that legal action is imminent.
Do invoices hold up in court? No, an invoice will not usually hold up in court. An invoice is simply a request for payment, but it's not a legal document and therefore not legally binding. You may be able to legally enforce an invoice if you also have a valid contract.
Generally speaking, contractors should collect payment for services within a reasonable amount of time, and this usually ranges from 30 to 90 days. In many states, payment is required within 30 days of the service being completed.
If the company forgot to bill you, it has four years to collect on the above types of debt or six years if the debt is a promissory note. If the company does not file a lawsuit to collect the debt before the applicable statute of limitations expires, it is too late for the company to collect on the debt.
If you have an unpaid invoice, here are some steps you can take to try and resolve the situation:
Jurisdiction and venue: You'll need to file in the correct court based on where the business was conducted or where the contract was signed. Amount in dispute: According to the California Courts Self-Help Guide, if the unpaid invoice is under $12,500, you may qualify for small claims court.
Most companies don't realise that they are entitled to chase invoices that go back as far as 6 years. It is important to remember that the time limit starts from when your customer last acknowledged owing the debt or made a payment on account against the invoice, not from when the invoice became due.
The e-invoicing system is mandatory for all B2B and B2G businesses with an annual aggregate turnover exceeding Rs. 5 crore. Starting 1 April 2025, businesses with an AATO of Rs. 10 crore or more must upload their invoices to the IRP within 30 days of issuance.
As per Rule 46 of the CGST Rules, 2017, a valid GST invoice must include: Supplier's details: Name, address, and GSTIN. Unique invoice number: Consecutive, unique, and not exceeding 16 characters. Date of issue.
Federal law says that invoices remain outstanding for up to 6 years; i.e., you can pursue a client for an unpaid invoice even if that invoice is 6 years old. Past that point, you'll probably need to seek legal action if you want to receive your payment.
Backdating invoices isn't inherently illegal—but misusing it to manipulate revenue or tax periods risks serious penalties.
Typically, businesses should bill for services or products promptly, but there isn't a specific law that prohibits billing for something from over two years ago directly. The statute of limitations for written contracts in California is four years, and for oral contracts, it's two years.
Maybe you've just discovered an old invoice that slipped through the cracks, or maybe you've been chasing down a customer who seems to have completely disappeared. Either way, you're probably wondering, how long can I keep chasing after this money? The short answer is for most debts, that limit is 6 years.