Immigration officials can accept monetary tips for a more efficient service in certain Central American countries. Tipping creates a bidding war in border queues. Back in April on the Honduras to Nicaragua border my group’s passports were processed first, despite me being third in the queue, because I outbid my competitors ahead of me. It’s part of the dark arts of tour leading.
However other countries forbid this kind of incentive. A few weeks after that issue I had a problem on the Costa Rica to Panama border as a client did not have the necessary entry stamp into Costa Rica. Negotiation on borders, in Spanish, can be challenging, but I knew I couldn’t ‘tip’ Mr Immigration in Costa Rica, or else I’d probably end up in a cell. After much arguing (read pleading) we eventually all got through fine. You never stop learning in this job.