How to reimburse a pastor for lost wages from his secular job to attend a conference

by Trying to do Things Properly
(Midwest)

The pastor of our tiny church receives his entire compensation as housing allowance.

He also works a secular job.

He would like to attend one or two pastoral conferences per year, and he has requested that our church pay all the related expenses for him and his wife.

For example, the first 4-day conference is 450 miles away and would require gas, food, conference and lodging expenses. Plus, he wants us to cover the lost wages at his secular job - 4 or 5 days for this particular conference - as he would not be paid for time off by that employer.

How would we do this, and how would this affect him for tax purposes?

I'm sure he would need the money up front or would have to use the church debit card on the trip.

Would he need to report the entire trip as income?

What tax filing requirements would the church have?