How does the date stamp work?

When the checkbox is ticked, today's date from your device clock is formatted as YYYYMMDD — 17 August 2026 becomes 20260817 — and inserted between the prefix and the sequence number. A Date badge next to the pattern confirms the exact date used, which matters if you generate invoices around midnight.

Can I generate numbers without a prefix?

Yes. Leave the Prefix field empty and the generator uses only the padded sequence, optionally with the date stamp and separator. With no prefix, no date, and separator set to None, the output is simply the zero-padded numbers themselves, which is handy for internal reference codes.

Are the generated invoice numbers guaranteed to be unique?

Within one batch, yes — each list is strictly sequential from the starting number, so there are no duplicates. Uniqueness across batches is your responsibility: restarting from 1 or reusing a range repeats numbers. Track your last issued number and resume from the next value each time.

What is padding and why does it matter?

Padding is the minimum number of digits, achieved with leading zeros: at padding 4, the number 7 becomes 0007. Consistent padding keeps numbers the same visual length and makes alphabetical sorting match numerical order in file lists and spreadsheets, which unpadded sequences famously break.

Can I export the generated numbers?

Yes. The result box shows the full list, one number per line, and offers a download that saves it as invoice-numbers.txt. You can also select and copy the text directly. The list updates live as you change settings, so download only after you have settled the final configuration.

Finance

Invoice Number Generator

Generate sequential, padded invoice numbers with optional date prefix.

invoicenumbersequentialbusinessbilling

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About the Invoice Number Generator

The Invoice Number Generator turns a set of formatting choices into a ready-to-use list of sequential invoice numbers, solving a chore every freelancer and small business meets at some point: how to number documents so they sort correctly, look professional, and never collide. You control five things — an optional text prefix, the starting number, how many numbers to generate, the digit padding, and a separator that can be a hyphen, slash, underscore, or nothing. A checkbox optionally prepends today's date in YYYYMMDD form, a scheme that keeps invoices naturally chronological even across restarts. The tool generates the list live, shows the first and last numbers and the total count as quick stats, and displays a pattern badge that previews the exact layout. Two guardrails keep output sane: the count is clamped to between 1 and 1,000, and padding is clamped to between 1 and 10 digits, each with an explanatory note when clamping happens. The finished list copies easily or downloads as a .txt file.

Hand-written guide

Examples

Input

Prefix INV, starting number 1, count 10, padding 4, separator Hyphen, date stamp off

Output

INV-0001
INV-0002
INV-0003
INV-0004
INV-0005
INV-0006
INV-0007
INV-0008
INV-0009
INV-0010

Note: Numbers are zero-padded to 4 digits, so 1 becomes 0001. The prefix and padded number are joined with a hyphen, producing ten sequential lines from INV-0001 to INV-0010.

Input

Prefix ACME, starting number 50, count 3, padding 3, separator Slash, date stamp on

Output

ACME/20260817/050
ACME/20260817/051
ACME/20260817/052

Note: The date stamp uses today's date in YYYYMMDD form (20260817). Each line joins prefix, date, and the padded sequence 050 through 052 with slashes.

Input

Empty prefix, starting number 0, count 5, padding 2, separator None

Output

Note: With an empty prefix and no separator, only the padded numbers remain. Starting at 0 is allowed, and the sequence runs 00 through 04.

How to use

1
Type an optional Prefix such as INV, or leave the field blank.
2
Set the Starting number, Count, and Padding fields — count and padding are clamped to 1-1000 and 1-10.
3
Pick a Separator from the dropdown: Hyphen, Slash, Underscore, or None.
4
Tick the Date stamp checkbox to prepend today's date as YYYYMMDD.
5
Read the Generated, Sample first, and Sample last stats, then copy or download the full list from the result box.

Common use cases

Numbering a new year's invoices with a date prefix so they sort chronologically.
Generating sequential ticket or receipt codes for a small event.
Producing order numbers for an online store before the sales system exists.
Creating reference numbers for client quotes under a shared prefix.
Resuming a sequence after a system migration by starting from the last used number plus one.
Standardizing document IDs across departments with a fixed padding scheme.

Best practices

Pick a scheme before you start billing — changing prefixes or padding mid-year breaks the sequence's consistency.
Always zero-pad: without padding, INV-9 sorts after INV-100 in almost every file manager.
Note that the date stamp uses your device's local date, so check the Date badge before generating a batch that spans midnight.
Use the clamping guards to your advantage, but watch for the amber notes so a typo of 10000 does not silently become 1000.
Keep a record of the last number used, because the generator always starts fresh from the value you enter.
Avoid the slash separator when the numbers will end up in filenames, where / is illegal on most systems.

Tips

Adopt a year-based prefix such as 2026- so each January you can restart the sequence cleanly.
Use the pattern badge to confirm the exact layout before copying or downloading a batch.
Prefer underscores over slashes when numbers will end up in filenames.
Generate in 1,000-number chunks for annual archives, keeping each file small enough to scan.

Frequently asked questions

The tool restricts generation to between 1 and 1,000 numbers to keep the list readable and the page responsive. If you enter 5,000 it clamps to 1,000 and shows an amber note telling you so. For longer sequences, generate the first 1,000, then change the starting number to continue where the batch left off.

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