How to Cheat Ma Bell


Fifth Estate # 266, September, 1975

Reprinted here are the instructions as they originally appeared in the FE for both the use of bogus credit card numbers (for free long-distance calls) and the subversion of computer-card billing (for reduced telephone bills). Also included is a description of the method whereby long-distance phone calls can be made by tapping into Bell’s own nation-wide test loop circuits, the bill for which goes directly to old Ma herself.

If you’re interested in the more sophisticated aspects of ripping off Bell (and other utilities), the two addresses listed below will furnish you with an astounding array of plans, instructions and schematic diagrams for the construction of such things as multi-frequency encoders (blue boxes), which will give you access to free long-distance calls literally anywhere, and “red boxes” which accurately reproduce the sounds transmitted to the operator by coins dropping into a pay phone. In addition, they also publish diverse material on methods of subverting gas and electricity meters with household items as simple as an ordinary vacuum cleaner.

Telephone Electronics Line
22035 Burbank Blvd.
Woodland Hills, Ca. 91364

TAP, Room 504
152 W. 42nd St.
N.Y., N.Y. 10036

As for the device which started all this, the “mute” or black box, plans for that are readily available to anyone who wants them at the main branch of the Detroit Public Library on Woodward. Just go upstairs to the Science and Technology Department and ask to see the June 1972 issue of Ramparts Magazine. For your convenience they even have xerox machines nearby with which to make your own personal copy. As Bell’s own hired experts will readily testify, it’s fun to build, easy to install and…it works!

Credit Card Calls

People should first be aware that just as the credit card code changes every year, so do the credit card phone numbers of some corporations.

Credit card codes are simple. They consist of ten digits and a letter at the end that matches the fourth digit. The first seven numbers are the phone number of the corporation that the call is billed to and the last three are a city code (Revenue Accounting Code (RAO, See list on this page.) The letter at the end corresponds to the fourth digit in the following manner: 1-E, 2-M, 3-U, 4-J, 5-Q, 6-A, 7-W, 8-Z, 9-H and 0-R.

Thus if you desire to bill a call to Honeywell of Minneapolis, their number is 941-5430. Add to this the RAO code which is 126. Then add the code letter–in this case it’s Q. Result: 941-5430-126Q. Here’s another one. The Detroit News number is 222-2332. Add the RAO, 083, and the 1975 letter code, M. You then have 222-2332-083M. Here’s some numbers you might remember: Wonder Bread in Boston is 893-5579-001Q, IBM in Miami is 377-2051-044M, or how about the Security Division of Illinois Bell Telephone, 727-2581-097M.

To make a credit card call always use a pay phone and not the same one all the time. Talk to the operator in a hurried business-like voice–tell her the number you want to call and then say, “Charge this to my credit card number….”

Often the operator will ask for the city or area code that the call is billed to, have this information ready. (Remember you’re an important executive.) It is always best to use a credit card number from the city that you are calling to, unless the corporation you’re representing has a branch office in your town.

Be sure to inform the person that you are calling of the possibility that company investigators will be checking up on the call in the future and will try to get info from them about you. People you call are in no way obligated to pay for the call or provide information to the phone company. The best way to handle it is to give fake names and addresses other than the ones the caller lives in. It’s also advisable that any person you call should never call you at any time. The phone company could easily put two and two together. One last warning: the operator may listen in on your call for a minute or two. Be sure you don’t say anything incriminating.

Use These RAO Codes to Make Your Own Credit Card Numbers

Area Code RAO and city
201 072, 074, 091, 094
202 032, 033, Wash. D.C.
203 020 Hartford
206 163 Seattle
209 254 Stockton 289 Fresno
212 017, 018, 021, 023, 024 072, 074, NYC
213 046, 182, 183, 184, 187, 332 Los Angeles
215 041, 043 Philadelphia
216 050 Akron 082 Cleveland
218 126 Duluth
301 011 Maryland
303 153 Colorado
305 044 Miami
306 137 Wyoming
308 237 Nebraska
312 097, 098, 234 Chicago
313 013, 096 Michigan 083 Detroit
304 177 St. Louis
404 022, 063 Georgia 035 Atlanta
408 293 San Jose
412 030 Pittsburgh
414 088 Milwaukee
415 158 San Francisco 187 Berkeley
416 185 Dayton
601 059 Mississippi
602 065 Arizona
604 493 Vancouver
608 201 Madison
612 126 Twin Cities
613 473 Ottawa
615 187 Memphis 047 Nashville
617 001 Boston 007 Massachusetts
702 271 Nevada
713 151 Houston
813 152 Tampa, St. Pete
914 141 N.Y. State

Reducing a Phone Bill

Anyone can decrease their phone bill–all you need is some clear Scotch tape, a razor blade and a little “know-how.” First of all, one should become aware of what IBM cards look like.

Look closely at your phone bill, borrow other people’s bills, check out computer bills from other companies besides Bell–you’ll notice that they’re all very similar. A computer reads your bill by means of little rectangular holes punched in various rows and columns. The number four is represented by a hole in the fourth row, while the letter “B” is two holes, one in row A and one in row two. A space is when no holes are punched.

It doesn’t take much smarts to discover where the holes are that represent the amount of money you owe. Compare your recent bill with last month’s bill, nothing will change except what you owe. If you owe $23.68 you will find a two, three, six and eight punched out in four consecutive columns from left to right.

Once you’ve found the holes that correspond to the amount of your bill, the next step is to change them around. This can be done with a keypunch machine like the ones on WSU campus in the basement of the science library. Of course, not everyone has access to a keypunch machine and it’s really not that necessary. All you need is a razor blade and some clear tape.

Once again, say your bill is $23.68. It would be quite simple to change $23.68 on the computer card to $3.68. By covering up the two hole with clear tape and cutting a new hole in the zero row, you can save twenty bucks. When covering a hole, use good quality tape that won’t yellow. Overlap the hole by only 1/8 of an inch all around, be sure it doesn’t cover another hole.

Cutting a hole is the hardest part. If it isn’t done just right, the computer will detect an error. When cutting a hole, line it up with other holes in the same row. This can be done by drawing faint pencil lines from hole to hole.

Always cover yourself in case something goes wrong. If your bill is $23.68, pay the entire amount and if your trick works, you will be credited for $20 on your next bill. In fact, you might even send in $25 so that the scheme won’t look like an overpayment by mistake but rather as an installment or a desire for future credit. The person who opens the envelope will see a bill for $23.68 and a $25 check. Only you and the computer will know about the $20 credit coming up next month.


The test loop-around lines that Bell maintains around the country consist of two “sides” which can be connected by dialing the appropriate numbers.

At present these numbers are 9996 and 9997 and, we are told, they can be used in conjunction with any local exchange.

If, for instance, you have a friend in New York who wishes to call you, you must first prearrange with him or her a method whereby they will notify you that they are about to call. The easiest way to do this is the old standby of having them place a person-to-person call to your number; the person they ask for will be your signal to refuse the call and hang up.

Pick up the phone again and now dial into your side of the loop-around using a local exchange the two of you have already agreed upon (if you choose, for instance, 875, you will dial 875-9996). If you are connected properly you will be greeted by a piercing, intermittent 1000 cycle tone.

Meanwhile, your friend (who, incidentally, must always call from a pay phone) has called the operator again in New York and asked to place a collect call to the number 875-9997 in Detroit. There may be a momentary delay while the Detroit operator verifies that the number is not a pay phone, then the operator will connect with you.

Immediately the 1000 cycle tone on your end will stop, you will say hello, the operator will ask if you wish to accept a collect call and your loop-around will be connected. And, come billing time, since the 9997 number is Bell’s own line, they have nowhere to send the charges but to themselves.

Note: on some loop-arounds you may experience an Intermittent click-click sound after being connected, but you shouldn’t worry about this. It goes without saying, of course, though we’ll say it anyway, that the person placing the long-distance call should always use a false name. A close colleague of ours, A. Nother Shady Character, tested the technique and reports success using an Ann Arbor loop-around, though he had some trouble going through Lansing on another. Other reports tend to bear out the usefulness of the method.