actionman
Emperor Mongoose
You may well be able to outrun the X-Boats, but the bank isn't going to let you access your account back on Regina until the financial data arrives.
And, the signal will propagate slowly but surely, until every bank on every Imperial world knows the character(s) have committed financial shenanigans. If their actions are bad enough, the characters might find themselves wanted in those Imperial systems as well. Even if they flee the Imperium, it's entirely possible that Imperial banks share data on untrustworthy individuals with non-Imperial banks and vice versa. The characters might find their range to roam getting smaller and smaller until they're stuck in the wilds outside the major empires, hiding out on Belgardian Sojourn or someplace like that. If a major Imperial bank puts a bounty on the characters, planetary authorities might arrest them and keep them in some absolute hole of a prison until the bank sends the money, or turn them over to a travelling Imperial magistrate who executes justice on the spot. Can't stop the wave.