What Is My ISP Number?

The phrase "ISP number" is used for at least four different things, and only one of them is really a number you can find on your provider's website. Before you paste anything into a form or read it out to support, it pays to know which one you actually need.

The short answer

When people say "my ISP number," they usually mean one of these:

Your account or customer number. The identifier your provider prints on your bill, used for billing and support.
Your ISP's name. The company you pay, if the question is really "who is my provider?"
An ASN. The autonomous system number that identifies your provider's network, like AS7922. This is the number lookup tools show.
Your public IP address. A number tied to your connection, not to your account, and one that changes over time.

No website can show your account number: it is private billing data. But the other three are easy to look up, so let's take them one by one.

1. Your account or customer number (the usual meaning)

If a support agent, an invoice, or a portal asks for your customer number, they mean the identifier of your account with your provider. Labels vary by company and country: account number, customer number, contract number, subscriber ID, or billing account ID all refer to the same thing.

You will find it:

On your latest bill or invoice, usually near the address block or payment details.
In your provider's app or customer portal, on the account overview page.
In the welcome email or letter you received when you signed up.

If you cannot find it, support can look up your account by name, address, or the phone number on the account. Treat this number as private: it is tied to your identity and payments, so do not post it online or share it with anyone who contacts you unprompted.

2. Your ISP's name

Sometimes "ISP number" is simply a confused way of asking "who is my ISP?" If that is what you need, our Who Is My ISP tool shows the provider behind your connection instantly. Keep in mind that the name a lookup returns is the network that carries your traffic, which can be a parent company or wholesale carrier rather than the brand on your bill. Our guide on how to find your ISP explains when and why those two answers differ.

3. Your ASN (the number in IP tools)

An ASN, or autonomous system number, looks like AS7922 or AS15169. It is the internet's routing identifier for a network, not anything tied to you personally. Lookup tools display it next to the provider name because it is the most precise way to say which network an IP address belongs to.

An ASN is useful when reporting network problems, comparing networks, or checking that a VPN moved your traffic off your home ISP. If you want the full explanation, we wrote a separate guide on what an ASN is.

4. Your public IP address

Your public IP address identifies your connection on the internet, not you personally. It can change when your connection resets, and often several customers share one address through carrier-grade NAT. If what you actually need is this address, see our page on what my IP is, or just check the live result on our homepage.

Which number do you actually need?

Billing or account questions: the account or contract number from your bill.
"Who is my provider?": an ISP lookup, which gives you the name and ASN.
Network debugging or abuse reports: the ASN, and your public IP at the time of the incident.
Setting up your own router: your connection details (PPPoE username and password), which are usually on your welcome letter or router label.

Where can I find my ISP username and password?

If your connection uses a login, for example PPPoE on DSL or fiber, the username and password come from your provider: check the welcome pack, a letter from the ISP, or the label on the router they supplied. This is different from your Wi-Fi name and password, and very different from anything an IP lookup can show. Treat connection credentials like any other password: keep them private and change them if you suspect they leaked.