Definition
Open-loop voucher
Prepaid card carrying a network logo (Visa, Mastercard) that is accepted anywhere — usually treated as a cash equivalent for tax purposes.
Open-loop cards are technically convenient: they work at every merchant. For tax purposes, in most jurisdictions they disqualify the gift card from tax-free employee benefit treatment — they count as wages.
In Germany an open-loop card breaks the Sachbezug exemption. In the UK such a card is essentially outside trivial benefits. In the Netherlands it likely lands in the WKR free space without a favourable exception.
For corporate campaigns aimed at tax optimisation, choose closed-loop, single- or multi-brand. Open-loop only makes sense for specific incentives where maximum spend freedom matters more than tax efficiency.