Coin Postage Issues "Physical Dimensions" COD & Envelope Stamp?

[world-city-distro]

I've got many coins to sell and started selling a few here and there.  In doing so I've noticed that not all postage is created equally.  Some listings offer an "envelope stamp" and others do not.  The "do-nots" offer first class or priority.  

Last week I was faced with the first class option at $3.49.  I was OK with it since the coin had value.  However, it arrived a COD was placed on the padded envelope for an additional $7.17 in WI.  The buyer paid it and I reimbursed him.  The not said " Tracking is only available for PARCELS or PRIORITY Mail.  Because this item does not have physical dimensions of a parcel priority postage is required.  POSTAGE DUE $7.17.   

I called the WI branch and was informed that a count does not inflate the padded envelope enough to be classified as "physical dimensions".  They said to place a couple of bottle caps or cardboard inside to puff out the envelope.  They also said that all states are supposed to enforce this issue and that WI is cracking down on it in so many words.  

My issue is that the label was generated from Ebay and my price point is based on the cost of shipping. Does Ebay know of this PD issue?  Will my other coins of non-value have surprise costs added if not stuffed with bottle caps? 

I understand that postage issues happen.  Usually, if there is one that needs more postage or if I paid too much it is addressed automatically through my account.  In this case, it was a COD to the buyer.  It makes me look bad as a seller when it is COD. 

So that is two questions for the community:

1: Why are "envelope stamp" options on some listings and some not? 

2: Why is there not up-front info of the thickness of a bubble mailer to qualify as a PM package? 

Inquiring minds wanna know.  Coin dealers and coin hustlers too.  

[zero29zero]

If you're talking about ebay standard envelope shipping when you say "envelope stamp" it's only available for coins selling for less than $20

The First Class parcel shipments need to have the envelope more that 1/4" thick, I use chunks of styrofoam in the envelope to bulk it up

[nobody*s_perfect]

The term "COD" means "Cash on delivery" and is a form of deferred payment in which the recipient gives their carrier payment for the item, which is forwarded to the sender.  What you have here is actually a case of Postage Due.

As noted by the post office, tracking is available only for packages; so mail pieces that qualify to be mailed as letters or flats (AKA Large envelopes) that are mailed with First Class package postage (which includes tracking) on them will be upgraded to Priority Mail status.  The recommendation to include a bottle cap or a slab of foam is to ensure that your piece doesn't qualify to be mailed as a letter or flat.

Letters must be not more than 1/4 inch thick.  Flats must be (1)  flexible, (2) not more than 3/4 inch thick, and (3) literally flat which the USPS defines as a variation in thickness not over 1/4 inch.  So putting a bottle cap in your envelope would disqualify the piece based on both items (2) and (3).

An alternative strategy would be to add enough cardboard to make the piece too thick to mail as a letter and too rigid to mail as a flat. I sometimes will just roll up the end of the padded envelope before I tape it, so the rolled-up end is more than 3/4 inch thick.

You can find more details and discussion about these categories of First Class mail (letters, flast, and packages) in the Domestic Mail Manual:

https://pe.usps.com/text/dmm300/101.htm

Entertaining illustrations on how to judge flexibility; rigidity (section 4.3):

https://pe.usps.com/text/dmm300/201.htm#ep1096318

[world-city-distro · Accepted solution]

Thanks for the info but "What you have here is actually a case of Postage Due" was bit rude.  You know I meant... No one likes the "actual" remarks. 

[deserdog]

I ship light weight items in small padded envelopes, 9X8, and use 2 pieces if cardboard, 8X7. The envelope is too large to be a letter, the the cardboard  makes it stiff so I ship as a first class parcel. Shipping varies from $3.62 to $4.26. I tape the 2 pieces of cardboard together so that the item cannot move around. The only times I gotten postal adjustments is when an envelope took a ride on a larger parcel, but I had the receipt from the post office and the post office had the picture, so everyone of those were credited back to me.