Many universities have a policy of not issuing a duplicate diploma for a degree, unless your original copy is incorrect, damaged, or lost.
One example:
University Policy forbids the issuance of multiple copies of a diploma. Each diploma is considered a one-of-a-kind legal document.
http://www.queensu.ca/registrar/diploma-replacements
Another example:
Replacement Graduation Diploma
- A graduation diploma will be replaced in the following cases:
- When a diploma has been lost or damaged.
- When the name of the holder has been changed under the regulations for the change of name process as per University records.
- Return of the original diploma with the request is required if the reason for replacement is due to damage or an official name change.
- In cases of lost or destroyed diplomas, the holder must submit a Statutory Declaration (form available below) to the University Registrar and have it signed and sealed by a Notary Public*, legally swearing that the original diploma has been lost or destroyed. The condition of the reissuance of a diploma in cases of loss or destruction is that if the original should be found at any time, the replacement diploma must be returned to the Registrar’s Office at Carleton University for cancellation.
http://carleton.ca/registrar/academic-evaluation/replacement-diploma/
The most explicit example:
Stanford University will not issue duplicate diplomas under any circumstances. This measure is taken to protect Alumni from identity theft. If your diploma was permanently lost or destroyed, a replacement diploma may be ordered from the Office of the University Registrar. You must fill out the Replacement Diploma Form, have it signed by a Notary Public ...
(PDF) The Stanford diploma is a unique document; neither copies nor duplicates are available.
https://registrar.stanford.edu/students/diplomas/replacement-diplomas
But then, there are other universities that have no, such, restrictions on duplicate diplomas.
The inconsistent policies between universities seem to suggest that some see it as a problem and some do not. Why would duplicate diplomas be a problem in practice?
My speculation, with no evidence provided:
- Giving a duplicate diploma to another person who coincidentally has the same name as you?
- This rule was born in an era before telecommunications and online services? You physically carried and showed your diploma to prospective employers and academic admissions officers?