How much can an overseas missionary deduct from income for SE tax purposes for business use of his home? Much of his ministry is one-on-one or else small group Bible studies and takes place in his home living room. Obviously this part of the house is not used exclusively for business purposes. Are you aware of any basis for claiming a larger office in home expense beyond what would be allowed under the "used exclusively" test?
Directly quoted from IRS Topic 509:
"Where the exclusive use requirement applies, you cannot deduct business expenses for any part of your home that you use for both personal and business purposes. For example, if you are an attorney and use the den of your home to write legal briefs and also for personal purposes, you may not deduct any business-use-of-your-home expenses. Further, under the principal-place-of-business test, you must determine that your home is the principal place of your trade or business after considering where your most important activities are performed and most of your time is spent, in order to deduct expenses for the business use of your home."
Since the pastor cited above does not use his living room regularly and exclusive for business purposes, no portion is deductible as a business expense. Further, if he is provided an office by the ministry, then it is unlikely that he will satisfy the principal-place-of-business test--an additional stipulation for business-use-of-home deductions.