[Dylan16807]

Have to? What happens if a random business accepts them for payment, and uses them for purchases at other accepting businesses?

[majewsky]

IANAL, but the association giving out the vouchers would probably sue for fraud, since the merchant acts like a member of the association even though they are not.

[Dylan16807]

That is a very very strange thing to consider fraud! Imagine applying the same logic to someone that will trade their wares for baseball cards.