Off screen explanations aside, the amount of time between SW and ESB is a little hazy. The Rebellion has probably been on the run most of that time. (They haven’t been on Hoth long enough to know about Wampas for example.) Whatever missions Has has done for them, hasn’t taken him close enough to Tatooine to drop off the cash.

The old Marvel book sidestepped all of this by having pirates rob Han and Chewie as they were on their way to pay Jabba. Other misadventures ensued to keep Han and Chewie back with Luke and Leia. Many issues later, they rescued Jabba after his disastrous attempt to get Han and keep the bounty for himself. Jabba forgave the debt in gratitude. Actually it was either accept Solo’s terms or get eaten by alien insects, but I digress. 😉

When the plot point for Empire was revealed to Marvel, they established Jabba was funding the pirate operation that robbed Han, (which Han had later ultimately destroyed) and the bounty was reinstated when the Hutt found out who was responsible.