Most authentic designer shoes come with labels (sewn to or printed on the interior of the shoe) and with paper tags.  Here are some common, and most likely fake, excuses that vendors of counterfeit shoes may use in an attempt to convince potential buyers that the shoes are real despite the absence of tags or labels.

1.  The shoes don't have labels or tags because they come directly from the manufacturer.  Designer shoes are not sold directly from the manufacturer, especially not at discount prices or in small quantities (i.e., different rules may apply if you were, for example, purchasing 100 pairs of Gucci pumps).

2.  We remove the labels before shipping.  Why would a vendor of designer shoes ever do this?  It makes no sense, and you should not be fooled for a second.  Part of the reason people spend extra money to purchase designer shoes in the first place is to possess a pair of shoes with that coveted label.  

3. The labels are removed because the shoes are secondhand.  Labels are often altered when the shoes are secondhand.  The labels are cut or a black line is drawn through the label.  This alteration to the label serves a couple purposes.  First of all, it protects against false returns (although most department stores will not accept returns without a receipt anyway).  And it makes clear to the buyer that the item is secondhand (so you will not be tricked into paying the full price for an old pair of Chanel shoes).  Labels of authentic designer shoes are never completely removed when they are sold through a secondhand market.

4.  The shoe does not come with a label or tags because it is a sample.  This excuse covers the vendor's tail on two ends.  First, he explains that there are no tags because the shoe is a sample, and second, he claims that this will account for any minor differences you might notice between the 'sample' and the designer item sold in the regular marketplace.  If a vendor were able to get his hands on a sample designer shoe, then most likely there would be some kind of 'sample label'.

Remember: In addition to tags and labels, most authentic designer shoes have the brand printed somewhere else on the shoe as well.  (For example, if you lift up the insole of a Prada trainer there should be an additional Prada logo stamped into the shoe.)  Be sure to look for this additional sign of authenticity.  Never purchase shoes online or through a secondhand market that has a 'No Returns' policy.  You should be able to return the shoes if you inspect them at home and see something suspicious.