If you didn't get the change order in writing, you may still have a case to get paid.
It's always better to get changes in writing, but in certain situations, an oral agreement may be enough. According to this case study from Sholfield Construction Attorneys in Colorado, "First, you need to understand the difference between true 'change orders' and 'extra work.' A change order alters the original contract by increasing, decreasing, modifying, or eliminating some aspect of the contracted work. True 'extra work' means work that is outside of, and entirely independent of, the contract."
Find out more about what rights contractors have to payment even in the absence of written authorization for changes or additional work.