A phrase denoting that the main intent of traveling out of town was to transact business. This trip may be combined with pleasure, but the primary purpose of the trip must be for business. If the business element of the trip were removed, the trip would not be taken. As long as the primary business purpose can be proven, the taxpayer may deduct all transportation and lodging costs, as well as 50% of meal expenses. This can be done even though part of the trip is for pleasure. However, if the main purpose of the trip is pleasure, then no expenses of any kind are deductible. Generally, the amount of time spent pursuing business versus pleasure activities is the determining factor in establishing primary business purpose. Keeping a log to document business activities is usually acceptable proof of business purpose in the event of an audit by the IRS.