Punctuation: No. - omit full stop or not? (2025)

I have a letter to write with a column subject of headings, such as "Order No.", "Order Date", "Delivery Date" etc etc. Each heading is followed by a colon and then the detail.

For the first item, "Order No.", should the full stop be omitted prior to the colon?

I would be grateful for clarification or comment.

As the forum dictionary tells us no as an abbreviation of number can be written either with or without the stop.

No. abbreviation for

• north(ern)
• Also: no ( pl Nos, nos) number

The choice is up to you.
I would write it with the stop, because that makes it clear that No is an abbreviation: Order No.:
However, you may prefer the cleaner look of Order No:
You can rely on the context to let people know that is an abbreviation.

(I speak American English, as you can see. I am under the impression that speakers of American English are more likely to include the stop after abbreviations while speakers of British English omit it. However, I may be mistaken. )

In American English style, the period (full stop) is required because "No." is an abbreviation for "Number." That is true no matter what follows it.

I also don't think a column heading requires a colon at the end if the list looks like a table.

Added in edit: This American English speaker thinks "No" is confusing without the period, because "No" is also a word. Even though readers will realize, after a moment's thought, that you can't possibly mean the word "no" in this context, why force your readers to figure things out? Using a period sends the message immediately and clearly.

Cagey said:

As the forum dictionary tells us no as an abbreviation of number can be written either with or without the stop.

No. abbreviation for

• north(ern)
• Also: no ( pl Nos, nos) number

The choice is up to you.
I would write it with the stop, because that makes it clear that No is an abbreviation: Order No.:
However, you may prefer the cleaner look of Order No:
You can rely on the context to let people know that is an abbreviation.

(I speak American English, as you can see. I am under the impression that speakers of American English are more likely to include the stop after abbreviations while speakers of British English omit it. However, I may be mistaken. )

Click to expand...

Thanks for that. I prefer without the stop. Oxford English Dictionary is the de facto ultimate authority on UK English, but provides no guidance on thsi. However, it does say that in UK English Mr, Mrs, Ms are use in all cases without a stop now; it also comments that American English does use the stop in those cases.

Egmont said:

In American English style, the period (full stop) is required because "No." is an abbreviation for "Number." That is true no matter what follows it.

I also don't think a column heading requires a colon at the end if the list looks like a table.

Added in edit: This American English speaker thinks "No" is confusing without the period, because "No" is also a word. Even though readers will realize, after a moment's thought, that you can't possibly mean the word "no" in this context, why force your readers to figure things out? Using a period sends the message immediately and clearly.

Click to expand...

Thanks for that, and I get your point. My only concern is the efficiency of what people do i.e. no stop is easier.

There is a thread that discusses the abbreviation for 'number':
Abbreviation of number - N, N°, Nr, Nbr, No? where the punctuation is discussed peripherally.

I write Mr, Dr, etc. without full stops but I generally still write No. with the stop. I have also seen it without.