How to investigate a notice of junk fax violation: Guide for fax
broadcasters and common carriers
If you are an honest common carrier or fax broadcaster and you are notified
by the FCC or individuals that you may be transmitting illegal faxes, you have a
duty to investigate those allegations and, if true, take steps to stop the
transmissions. If you do not take action, you can be held liable for the illegal
faxes (see Junk fax Q&A for details).
The purpose of this page is to assist you in determining whether you are
sending illegal fax transmissions.
There are many ways you can use to determine whether your customer is using
your company to send illegal fax transmission. Here are some questions to ask:
- Look at who the company is that is generating the calls, e.g., a Google
search or other research. Are they a legit company? What are they sending
the faxes for? What is the content of the faxes? Who are the recipients?
- How did the company supposedly get the list of fax numbers? Does their
story make sense to you, i.e., is the story consistent?
- Can the customer explain how they are generating the call volume and
tell you their customers and how much each one of their customer is sending
out? Do the numbers add up, i.e., can they explain and justify at least 80%
of the call volume? Have you heard of their customers that are supposedly
generating this business? Have you confirmed with them that they are
actually sending out these faxes and supplied the numbers?
- Look at your own phone records. How many calls are being made per day?
Are the numbers all over the country? Sort the numbers in numerical order
and find out how many calls per month are made to each phone number.
- Randomly pick a few of the numbers from the phone bill. Ask your
customer to explain to you who owns that number and how they know that and
ask them for proof that they got "express consent" to send the fax.
- Send a fax to a few randomly selected numbers on your phone bill for
that customer that asks the recipient to fax you a copy of the fax that was
sent out at the time of the call. Examine the fax.
- Look at the FCC website and see if the customer is listed on the
Telecommunications Consumers Division - Unsolicited Faxes
- Look at the copy that is being sent out by the customer. Does it look
like a legal fax sent to people who provided express consent? Or does it
look like a junk fax?
Indicators that your customer is sending illegal faxes:
- Your customer can't supply proof of permission of the numbers you
randomly select from the numbers that they dialed.
- The number of calls per day frequently exceeds 1 million (only junk
broadcasters have that kind of volume; nobody else sends out legit faxes in
- The number of unique numbers dialed during the month >1 million (nobody
has a reach that large unless they have war dialed fax numbers)
- Your customer can't give a credible explanation as to how they are
generating the call volume (i.e., they should be able to provide a list of
their top 20 customer and the # of faxes sent by each customer per month) so
that you can verify that data with the companies themselves
- The material they are sending out looks like a junk fax
- The "story" the company gives as to how it got the fax numbers doesn't
make sense, e.g., a fly by night company that nobody ever heard of doesn't
have 1 million fax numbers
- The phone numbers supplied by the company contain lots of consecutive
numbers. That's VERY unlikely in any legit fax list.
- The same phone numbers are being called over and over again. Most legit
senders rarely fax the same number more than once a month.
- If you are a common carrier with a fax broadcaster customer and over 1
million unique numbers are dialed every month and (1) there are many
consecutive numbers (after sorting) and (2) the number of calls to every
number is approximately the same, e.g., 5 calls per month on every number,
it is an EXCELLENT indicator of an illegal fax broadcaster.
Telltale signs by analyzing the phone records
- almost always <1 million calls a day (no legit broadcaster has volumes
anywhere close to 1 million calls a day)
- consecutive numbers should be rare
- # of unique phone numbers dialed over the entire month is <1M
- <5 million calls/month
- Average number of calls per unique phone number: <2 (i.e., take total
# of calls and divide by # of unique phone numbers)
Illegal broadcaster telltale signs:
- >1 million calls/day on some or most days
- >5 million calls/month
- Average number of calls per unique phone number>=2 (since blasters
hit the same numbers over and over again with different promos)
- >1M unique numbers dialed over the entire month. Note: if >5M unique
numbers are dialed over the entire month, this is a dead giveaway of an
illegal use since that is virtually every fax machine in the US that has not
been "removed" from a fax broadcaster database.
- in certain areacode/prefixes, every number in a large numeric range is
dialed approximately (or exactly) the same # of times where the # is >1.
- The data is chunky as you go through it with some areas (consecutive
numbers) having high call rates and other areas with call rates that are
- >1M phone numbers with >5 calls per month
- their top 20 customers are names nobody has ever heard of
- if you sue them, they refuse to comply with discovery object to
- they file a motion to quash if you try to subpoena their phone records
from their phone supplier
- when you contact them about the problem and ask them what happened after
they investigated, they refuse to tell you
- they tell you excuses as to why your "notice" does not constitute legal
notice or tell you they are ONLY required to remove your number that you
- their removal number doesn't identify who the company is
- the removal numbers they use belong to a foreign company
- they get their fax numbers from a foreign company or do most of their
business from orders from a foreign country
This section isn't that useful because legit data can be quite noisy. For
reference purposes only....
Statistically speaking, suppose you are a LEGIT fax broadcaster with 10 big
customers. Suppose each of your customers just huge and each one has 50% of the
total fax numbers in the US. Suppose each customer sends 1 fax a month.
Chance of exactly 0 fax: .001
Chance of exactly 1 fax: .01
Chance of exactly 2 fax: .045
Chance of exactly 3 fax: .120
So it's a normal curve where most people get 5 faxes and it tapers off on
either side with an exponential decay.
But that's not the usual situation. Say a legit fax broadcaster has 10
companies, each with a list that might be 10% of the total fax numbers in the
US. So let's say every customer sends 1 fax per month. We'd expect to get, on
average, only 1 fax per month since collectively, the advertisers cover all the
fax machine. But some people won't get any faxes and some will get more than 1
Chance of exactly 0 fax: .348 (i.e., 9**10/10**10)
Chance of exactly 1 fax: .387
Chance of exactly 2 fax: .193
Chance of exactly 3 fax: .057
Chance of exactly 4 fax: .011 (i.e., 9**6/10**10 * (10!/(6!4!))
Chance of exactly 5 fax: .001
Chance of 6 or more fax: .003 (i.e., 1 - (sum of probabilities above)
But if every advertiser is using the same list (as in an illegal fax
broadcaster), we'd expect that the distribution of # of calls per number is
relatively flat, i.e., in the "ideal" case, every number in the database is
called exactly the same number of time (with minor variances for calls that
can't be completed). So the distribution of calls should be relatively flat.
Unfortunately, there are way too many possibilities that can introduce noise
into the system, e.g., a big legit company sends 5 faxes to everyone, another
company sends 2 faxes, etc. So it's hard to be definitive as to the