How to comfortably avoid the combining of promotions

Graciously offer to extend the other promotion

If a table of four wants to use a birthday card and another promotion, first tell them they may only use one. (All your restaurant promotions should say not combinable on them).  Since we assume that they are visiting on or close to their birthday, graciously offer to extend the other promotion if they balk at all.  If they prefer to use the other promotion however, offer to extend their birthday card expiration date by about a month.  You should write the new expiration date right on their birthday card.  In this way, you diffused the situation, impart good will by doing the customer a “favor” and, most important, gave them the incentive to return again.  This also applies to two birthday cards being used at the same table.  If the number of persons in the party is large, you may want to overlook this guideline.