The durations specified on referral listings are just estimates, and you can always negotiate with the customer for a different amount of time. After you claim a booking, we recommend that you reach out to the customer for more information if you cannot assess whether or not you’ll be able to complete everything in the time estimated.
It’s a good idea to be upfront with your customers before you start and let them know they may need to add time to complete the job to your level of satisfaction. If you or the customer don't want to add hours to the booking, you are not obligated to stay past the estimated duration.
When you negotiate adding time to a job, the customer must approve the addition. If you don't confirm it with them, you won't be eligible for additional hourly pay.
This works a bit differently for booking made through Wayfair or Walmart. You can learn more about that process here.