A seed repeats the same list. The area code on the US rows is 212 only as a familiar shape around that reserved exchange. The exchange, 555-01, is the part that keeps the number out of service.
How to use
- Choose the US 555 range or the UK 01632 range.
- Ask for 1 to 10 numbers and set a seed if you need the list again.
- Press Generate. Do not dial the results. Reset restores three US numbers from seed 42.
Formula / how it works
Why these ranges. In the North American plan, 555-0100 through 555-0199 are reserved for fiction. Directory drama, textbooks and user-interface samples are supposed to use them so a prop number does not land on a person. Ofcom publishes 01632 960000–960999 for the same reason in the United Kingdom. This tool will not invent a mobile range, a toll-free range or an international country code. The random number generator will give you bare digits with no claim about a telephone plan. Use that when you do not want the digits to look like a phone number at all.
The seed. The list comes from a fixed sequence started by the seed, not from the clock. Seed 42, three US numbers, is always (212) 555-0160, then 0144, then 0185. Change the seed or the count or the region and the list changes. Ask twice with the same three inputs and you get the same rows, which is what you want when a screenshot and a later run have to match. Duplicates inside one list are skipped, so a request for three numbers is three different numbers. The blocks are finite: 100 US lines and 1,000 UK lines. Asking for 10 is inside both.
Format. US rows look like (212) 555-01xx. UK rows look like 01632 960xxx, with a space after the trunk code. Neither row adds an extension, a plus sign or a country prefix. If your form wants E.164, you are outside what this page will pretend to know. Add the prefix yourself only if you understand that the result is still a fictional subscriber number.
What you must not do with them. Do not put them in a message that asks a real person to call, pay or confirm an account. Do not scrape them into a dialler. The reservation exists so that a story can show a number. A tool that emitted ordinary mobile numbers would be handing out strangers’ lines. This one refuses that job. Ten numbers is the cap so the page stays a sample, not a list to import.
The region control. “us” selects the 555 block. “uk” selects the Ofcom block. There is no third country, because a reserved range the page does not know would be a guess, and a guess is how a real number leaks into a demo.
Worked examples
Three US numbers from seed 42
Inputs: Region: us | How many: 3 | Seed: 42
Choose region us, how many 3 and seed 42. The first line is inside 555-0100 to 555-0199.
Result: Region: US fictional (555-0100–555-0199)
Seed: 42
Count: 3
1. (212) 555-0160
2. (212) 555-0144
3. (212) 555-0185
These ranges are reserved for fiction in film and television. They are not a real person's number.
Two UK drama numbers from the same seed
Inputs: Region: uk | How many: 2 | Seed: 42
Choose region uk, how many 2 and seed 42. Both numbers sit in 01632 960000 to 960999.
Result: Region: UK Ofcom drama (01632 960000–960999)
Seed: 42
Count: 2
1. 01632 960601
2. 01632 960448
These ranges are reserved for fiction in film and television. They are not a real person's number.
Use cases
- A prop number in a script or a storyboard.
- Sample rows in a contact form you are designing.
- A test database that must not contain a real subscriber.
- A screenshot that has to match a later run of the same seed.
Tips & limitations
- Do not dial them and do not text them to customers.
- Keep the seed if a test has to reproduce the list.
- Use the plain random-number tool when the digits should not look like a telephone.
- Stay inside the two regions. There is no safe guess for other countries.
FAQ
Will these numbers ring?
They are in ranges reserved for fiction. Do not dial them. They are not assigned here as anyone’s line.
Why does every US number contain 555-01?
That exchange block, 0100 through 0199, is the reserved slice. The tool will not leave it.
Why is the area code 212?
It is a familiar shape around the reserved exchange. The part that makes the number fictional is 555-01, not the area code.
Can I have a different list from the same seed?
Change the region or the count. The same region, count and seed always rebuild the same rows.
Can I generate a whole city’s worth?
No. The cap is 10, and the US block only contains 100 numbers. This is a sample, not an export.
Are the numbers uploaded?
No. They are calculated in the browser from the seed.
Results are calculated from the values you enter. Double-check measurements and allow a margin before buying materials or making decisions.