Voucher Codes vs Coupon Codes

I was under the impression that a voucher represented a dollar amount that could be spent. However, by default it's only allowing the code to be used once, so, if someone used $5.00 of $20.00 voucher, they are unable to use the remaining $15.00? Can this be changed in the code somewhere, and where?

Thank you!

Hello Dawn,

Currently, voucher in EShop only allow customer to use it one time, then it will be not available.

Sincerely, Giang