# How does the government check the validity of postage stamps? **URL:** \ **Category:** Factual Questions\ **Created:** [March 12, 2007, 11:42pm UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680 "2007-03-12T23:42:57Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Absolute](https://avatars.discourse-cdn.com/v4/letter/a/b2d939/32.png) [@Absolute](https://boards.straightdope.com/u/Absolute)\ **Post date:** [March 12, 2007, 11:42pm UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/1 "2007-03-12T23:42:57Z")
When you mail a letter, how does the government verify that what you’ve pasted in the upper-right corner is actually an official USPS postage stamp? There are so many stamp designs, and none of them appear to have any kind of anti-counterfeiting component - no microprinting, foil strips, or any of that. What’s to stop me from just printing some random artwork onto adhesive-backed labels, and using some kind of tool/press/whatever to produce that sawtooth pattern on the edges? ---
**Author:** ![R.P.McMurphy](https://avatars.discourse-cdn.com/v4/letter/r/7993a0/32.png) [@R.P.McMurphy](https://boards.straightdope.com/u/R.P.McMurphy)\ **Post date:** [March 12, 2007, 11:50pm UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/2 "2007-03-12T23:50:31Z")
[QUOTE=Absolute] When you mail a letter, how does the government verify that what you’ve pasted in the upper-right corner is actually an official USPS postage stamp? There are so many stamp designs, and none of them appear to have any kind of anti-counterfeiting component - no microprinting, foil strips, or any of that. What’s to stop me from just printing some random artwork onto adhesive-backed labels, and using some kind of tool/press/whatever to produce that sawtooth pattern on the edges? [/QUOTE] I don’t know but I always put a stamp on the envelope. I figure that if they can develop handwriting recognition software that works pretty well, they can develop software that can recognize a legitimate stamp. ---
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [March 12, 2007, 11:50pm UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/3 "2007-03-12T23:50:38Z")
The facer/canceler is looking for invisible optical signatures - namely, special inks used in printing stamps or postmarks. I’m not going to say whether or not they’re infrared, ultraviolet or a mix of the two. If you can fake the invisible optical characteristics for less than 39¢ worth of effort, your letter will probably go through un-noticed, assuming your effort actually looks like a stamp and the carrier who delivers the letter to the recipient’s mailbox doesn’t notice anything funny. Of course, making counterfeit stamps would be postal fraud, a tidy little Federal crime that would put you in a whole new world of hurt, and on a first-name basis with the Secret Service. ---
**Author:** ![Absolute](https://avatars.discourse-cdn.com/v4/letter/a/b2d939/32.png) [@Absolute](https://boards.straightdope.com/u/Absolute)\ **Post date:** [March 12, 2007, 11:58pm UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/4 "2007-03-12T23:58:49Z")
Ah, okay - special inks. I didn’t think of that. ---
**Author:** ![scm1001](https://avatars.discourse-cdn.com/v4/letter/s/c4cdca/32.png) [@scm1001](https://boards.straightdope.com/u/scm1001)\ **Post date:** [March 15, 2007, 12:18am UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/5 "2007-03-15T00:18:33Z")
[QUOTE=gotpasswords] The facer/canceler is looking for invisible optical signatures - namely, special inks used in printing stamps or postmarks. I’m not going to say whether or not they’re infrared, ultraviolet or a mix of the two. . [/QUOTE] The canadian post office is not so shy. " During the printing process the stamps are tagged with a fluorescent ink on all four edges. Tagging permits stamps affiÌ to envelopes to be detected by machine and is also an antifraud tactic for corporate revenue protection" from [Home](http://www.upu.int/philately/en/making_postage_stamp.html) ---
**Author:** ![Triskadecamus](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@Triskadecamus](https://boards.straightdope.com/u/Triskadecamus)\ **Post date:** [March 15, 2007, 12:23am UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/6 "2007-03-15T00:23:17Z")
Ten years or so of sorting mail out to delivery customers make the average postal carrier an absolute wizard at noticing bad stamps, overweight envelopes, and other such things. He won’t always get every one, but over enough repetitions to actually pay for a single printing run, you are gonna get nailed. After that, the postal inspectors are on to you, and they are just annoyingly relentless. Tris ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 15, 2007, 12:36am UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/7 "2007-03-15T00:36:43Z")
[Postage stamp security features](http://www.linns.com/howto/refresher/security_20000605/refreshercourse.asp?uID=). ---
**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\ **Post date:** [March 15, 2007, 12:38am UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/8 "2007-03-15T00:38:51Z")
Would anybody really go to the trouble of forging stamps just to save a few pence on postage? Too much trouble for too little profit. Faking rare stamps to sell to collectors, though, is a different matter. ---
**Author:** ![psychonaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/psychonaut/32/4655_2.png) [@psychonaut](https://boards.straightdope.com/u/psychonaut)\ **Post date:** [March 15, 2007, 12:53am UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/9 "2007-03-15T00:53:44Z")
[QUOTE=Peter Morris] Would anybody really go to the trouble of forging stamps just to save a few pence on postage? [/QUOTE] Yes, they would. A few years back someone “donated” to our organisation several hundred pounds’ worth of forged stamps which he bought on the street for a pittance. He insisted they were safe to use because he’d been using them for months without getting caught. :rolleyes: ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [March 15, 2007, 2:11am UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/10 "2007-03-15T02:11:14Z")
[QUOTE=gotpasswords] If you can fake the invisible optical characteristics for less than 39¢ worth of effort, your letter will probably go through un-noticed, assuming your effort actually looks like a stamp and the carrier who delivers the letter to the recipient’s mailbox doesn’t notice anything funny. Of course, making counterfeit stamps would be postal fraud, a tidy little Federal crime that would put you in a whole new world of hurt, and on a first-name basis with the Secret Service. [/QUOTE] Isn’t it usually the Postal Inspectors who investigate this kind of thing? Or does the SS do it because counterfeiting is involved? ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 15, 2007, 2:16am UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/11 "2007-03-15T02:16:23Z")
[QUOTE=friedo] Or does the SS do it because counterfeiting is involved? [/QUOTE] Yes, under Title 18 of the US Code: [ > [@](#): > > The Secret Service has exclusive jurisdiction for investigations involving the counterfeiting of United States obligations and securities. This authority to investigate counterfeiting is derived from Title 18 of the United States Code, Section 3056. Some of the counterfeited United States obligations and securities commonly dealt with by the Secret Service include U.S. currency and coins; U.S. Treasury checks; Department of Agriculture food coupons and U.S. postage stamps. ]([http://www.secretservice.gov/counterfeit.shtml](http://www.secretservice.gov/counterfeit.shtml)) ---
**Author:** ![urban1a](https://avatars.discourse-cdn.com/v4/letter/u/e47c2d/32.png) [@urban1a](https://boards.straightdope.com/u/urban1a)\ **Post date:** [March 15, 2007, 2:44am UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/12 "2007-03-15T02:44:51Z")
[QUOTE=gotpasswords] The facer/canceler is looking for invisible optical signatures - namely, special inks used in printing stamps or postmarks. I’m not going to say whether or not they’re infrared, ultraviolet or a mix of the two. If you can fake the invisible optical characteristics for less than 39¢ worth of effort, your letter will probably go through un-noticed, assuming your effort actually looks like a stamp and the carrier who delivers the letter to the recipient’s mailbox doesn’t notice anything funny. Of course, making counterfeit stamps would be postal fraud, a tidy little Federal crime that would put you in a whole new world of hurt, and on a first-name basis with the Secret Service. [/QUOTE] But…How about postage meters in companies. You just buy your ink anywhere as long as it is red. You don’t have to buy it from the Post Office. And, can’t you now print your own postage from the USPS website? Bob ---
**Author:** ![IAmNotSpartacus](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@IAmNotSpartacus](https://boards.straightdope.com/u/IAmNotSpartacus)\ **Post date:** [March 15, 2007, 2:54am UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/13 "2007-03-15T02:54:36Z")
The printouts from the [USPS.com](http://USPS.com) website have barcodes and label numbers that probably will send up a red flag since the USPS expects to have the address info on file from when the label was created. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 15, 2007, 2:59am UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/14 "2007-03-15T02:59:52Z")
[QUOTE=urban1z] But…How about postage meters in companies. You just buy your ink anywhere as long as it is red. You don’t have to buy it from the Post Office. [/QUOTE] Modern postal indicia have [digital security](http://www.usps.com/history/cs01/c2k-8.htm) features: > [@](#): > > The Information Based Indicia (IBI) is part of the PTM security architecture and the objective to secure postage against counterfeit attack. The goal is to incorporate technology into the postage mark that makes it harder to counterfeit, that makes counterfeiting easier to detect, and that offers value beyond postage. > > Unlike traditional postage meter indicia, each IBI is unique. IBI incorporates digital printing of indicia that includes human readable and machine readable (barcode) data containing, among other information, certain “security critical” data elements. The IBI also incorporates cryptographic services which digitally “sign” each indicium making it possible to verify its authenticity. ---
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [March 15, 2007, 3:34pm UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/15 "2007-03-15T15:34:12Z")
[QUOTE=urban1z] But…How about postage meters in companies. You just buy your ink anywhere as long as it is red. You don’t have to buy it from the Post Office. [/QUOTE] Go try to find a red ink printer cartridge that isn’t specifically made for a postage meter. I dare ya. Plain red ink is simply not used in normal inkjet printers as it’s not part of the 4-color printing process (cyan, magenta, yellow, black) so you won’t find red ink cartridges. The red ink that is available is also murderously expensive. We used to have a personal postage meter a few years ago, but got rid of it when we realized that the $40 cartridges from Pitney Bowes were only good for three or four months, whether or not we used the thing. ---
**Author:** ![butler1850](https://avatars.discourse-cdn.com/v4/letter/b/779978/32.png) [@butler1850](https://boards.straightdope.com/u/butler1850)\ **Post date:** [March 15, 2007, 3:39pm UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/16 "2007-03-15T15:39:19Z")
How does the likes of [stamps.com](http://stamps.com) do it then? You can print your legal stamp using your home printer. What’s to stop me from printing a sheet, then copying multiple times on my color copier/scanner/printer? ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [March 15, 2007, 4:07pm UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/17 "2007-03-15T16:07:20Z")
[QUOTE=Peter Morris] Would anybody really go to the trouble of forging stamps just to save a few pence on postage? Too much trouble for too little profit. Faking rare stamps to sell to collectors, though, is a different matter. [/QUOTE] That’s my thought too. And collectors aren’t handling thousands of pieces of mail with stamps. They have the time to really study an item that they are considering buying and the knowledge to make that study worthwhile. ---
**Author:** ![postcards](https://avatars.discourse-cdn.com/v4/letter/p/8e8cbc/32.png) [@postcards](https://boards.straightdope.com/u/postcards)\ **Post date:** [March 15, 2007, 4:13pm UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/18 "2007-03-15T16:13:25Z")
[QUOTE=gotpasswords] …Plain red ink is simply not used in normal inkjet printers as it’s not part of the 4-color printing process (cyan, magenta, yellow, black)… [/QUOTE] [Plain Red Ink Carts.](http://www.bhphotovideo.com/bnh/controller/home?O=1119&A=details&Q=&sku=319799&is=REG&addedTroughType=categoryNavigation) Actually, red and green are more and more becoming common in photo inkjet printers; the Canon cartidges linked to above are available at just about any Staples or other office supply store. ---
**Author:** ![yoyodyne](https://avatars.discourse-cdn.com/v4/letter/y/a9a28c/32.png) [@yoyodyne](https://boards.straightdope.com/u/yoyodyne)\ **Post date:** [March 15, 2007, 4:49pm UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/19 "2007-03-15T16:49:56Z")
[QUOTE=butler1850] How does the likes of [stamps.com](http://stamps.com) do it then? You can print your legal stamp using your home printer. What’s to stop me from printing a sheet, then copying multiple times on my color copier/scanner/printer? [/QUOTE] The stamps you print have a bar code serial number that is read at the post office. The post office sends the serial to [stamps.com](http://stamps.com), which transfers the postage to the post office, looks up which account it sent that number, and reduces your account balance for the amount. If you copied the stamps I suspect it would bill multiple times for each stamp serial number it saw (rather than reject it) and your [stamps.com](http://stamps.com) balance would decrease accordingly. ---
**Author:** ![cmkeller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmkeller/32/118_2.png) [@cmkeller](https://boards.straightdope.com/u/cmkeller)\ **Post date:** [March 15, 2007, 4:55pm UTC](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680/20 "2007-03-15T16:55:37Z")
Never mind being able to tell real stamps from fake ones - how do they verify the amounts? Those special inks used in different concentrations? Automatic flagging of anything that isn’t standard first-class postage for manual checking? Random auditing as deterrent but no real checking? When they changed the price of stamps from 37 cents to 39 cents, would they have noticed if I didn’t bother affixing the additional 2 cent stamp to my envelopes until I ran out of the old ones? [Next page](https://boards.straightdope.com/t/how-does-the-government-check-the-validity-of-postage-stamps/395680.md?page=2)