I am talking about something you should pay. "Invoice" here doesn't mean the proof of payment. Sometimes I am told to pay my "bill", and sometimes they may refer to the similar paper (physical or virtual) as "invoice". The only difference I can think of is that "invoice" seems to be something you pay before you use while "bill" is the opposite. But this distinction is not clear since my university also calls the tuition fee as invoice now (I am already studying when I pay the "invoice").

Could someone tell me the difference?


6 Answers 6


An invoice is a request for payment that contains information necessary to remit payment to the issuer. Normally that would include the issuer's name, address, terms of payment and if necessary an account number. The invoice also is given a number - a unique key identifier with respect to the issuer.

Later, this number can be referred to in future correspondence. A bill may or may not include any of the above, but an invoice usually will.

Rather, the distinction between these two words is more a matter of custom and the business in question being transacted. For example, a lawyer bills a client, for billable hours. In the abstract, "you should pay your bills on time." Work that is commissioned will usually generate an invoice.

Bill in the sense we're discussing is Anglo Saxon and dates from the 1400s, and invoice is French (envoyer, "dispatch") from the 1500s. You might make the case that invoices are attached to things that are delivered, but in practice it seems that various trades over time have selected one term or the other by tradition and custom.

  • The first paragraph can apply to bills, too. In fact, you bill your clients or you invoice them, same thing. There are different usages. I number my invoices but I would not call that a unique key identifier. A bit long winded, don't you think? Lawyers and other independent professionals can be said to invoice their clients.
    – Lambie
    Commented Nov 20, 2019 at 0:37
  • My experience is that an invoice lists the products or services, making it suitable for bookkeeping records for expenses (e.g. for income tax purposes), whereas a bill is simply a statement that states the amount owed, and possibly lists the relevant invoice numbers. A bill goes to "accounts payable", but is not suitable for bookkeeping. Commented Nov 20, 2019 at 1:44

An invoice is a formal written demand for payment: if you accept that it is valid then you should pay it in accordance with the terms of the contract, e.g. within 30 days. A bill is simply a list, so might contain details which are not necessary for the invoice, and may or may not be a demand for immediate payment. So you could imagine being told "Here is a bill showing everything you've ordered. I'll send you an invoice as soon as it's been delivered."

  • 1
    You've hit on the answer with the word formal, but note that the two terms can be used interchangeably and refer to the same document or process in every particular. Businesses almost invariably use the term invoice, but an invoice is just a specific type of bill.
    – Robusto
    Commented Feb 26, 2011 at 12:17
  • Polite disagreement here. A waiter brings you a bill, a car dealer gives you an invoice. I'm seeing the "list" business as being a red herring with this one. What really makes the invoice stand out is the number or code it contains for future reference. But by and large the choice of word will be dependent on the kind of business in question.
    – The Raven
    Commented Feb 26, 2011 at 12:43
  • Not exactly what I want to ask, but thank you for the explanation on the meanings.
    – LLS
    Commented Mar 2, 2011 at 13:54
  • Ah, but what about a "Pro-forma Invoice"? This is "how much you would have to pay if you actually decided to agree to the transaction". Not exactly a demand for payment, or perhaps, a hypothetical demand for hypothetical services rendered...?
    – user597
    Commented Mar 3, 2011 at 1:00
  • @mickeyf: But then a pro-forma invoice isn't really an invoice, in the same way that fake gold isn't actually gold...
    – psmears
    Commented Mar 4, 2011 at 9:33

A bill is "an amount of money owed for goods supplied or services rendered, set out in a printed or written statement of charges", while an invoice is "a list of goods sent or services provided, with a statement of the sum due for these"; the NOAD reports also that invoice means bill.

In some contexts, invoice is used as synonym of bill; in other contexts, invoice is used to mean a document that contains a list of goods or services and the bill, but it contains also other specific data that are required by specific laws/regulations.

  • 1
    A bill can also be used to mean such a document. There is no substantial difference between the two terms, except that invoice is more formal and technical.
    – Robusto
    Commented Feb 26, 2011 at 12:11
  • 1
    In my mind, invoice has a connotation of more details in the document and tracking (an invoice number), that a bill may not have. They bring you a bill at a restaurant, you get an invoice from a supplier. You'd never use invoice in a restaurant or in a department store.
    – Wayne
    Commented May 24, 2011 at 20:51

I believe that invoice does not presuppose obligatory payment.

For example, as developer of plug-ins for different CMSs (Content Management Systems) I can obtain a copy of any commercial СТS as developer-contributor.

Nevertheless, I frequently have to fill and submit an invoice with a zero price for billing system of a vendor.

  • It can be one of the difference. But I guess it's not that important since my tuition is practically obligatory.
    – LLS
    Commented Mar 3, 2011 at 7:34
  • This is the most important information right here. In accounting the compulsory status of the bill makes it very different from an invoice. e.g. an invoice might mention "not a bill" and therefore you cannot include it in your A/P reports!
    – Sebas
    Commented Nov 12, 2016 at 11:34

Am I wrong in saying:

  • A bill quotes an already delivered, after the fact, goods and services (e.g., utility bill).
  • An invoice is presented prior or at delivery time for a defined quantity of goods and services.
  • 1
    It's not that clear cut. Raven's answer covers how things work. Commented Mar 22, 2012 at 10:25

In short:

  • Bill: an account of money owed for goods etc., e.g. an electricity bill.
  • Invoice: a list sent with goods giving details of price and quantity.
  • 2
    I'm not the downvoter. Let me tell you though that Bills (esp. "Bill of materials" ;-) are itemised lists. I up-voted @The Raven's answer though. I should know a thing or too about bill and invoice: I run/install/migrate billing system for a living. Commented Apr 14, 2011 at 15:10

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