Answer
When there are two or more borrowers, but one or more will not occupy the property as a principal residence, the maximum mortgage is limited to a 75 percent LTV. However, maximum financing, as described in HUD Handbook 4155.1 is available for borrowers related by blood, marriage or law (spouses, parent-child, siblings, stepchildren, aunts-uncles/nieces-nephews, etc.), or for unrelated individuals that can document evidence of a family-type, longstanding, and substantial relationship not arising out of the loan transaction.
All borrowers, regardless of occupancy status, must sign the security instrument and mortgage note.
If a parent is selling to a child, the parent cannot be the co-borrower with the child on the new mortgage unless the loan-to-value is 75 percent or less.
To reduce risk exposure, mortgages with non-occupying co-borrowers are limited to one-unit properties if the LTV will exceed 75 percent. While we do not object to legitimate transactions in which non-occupant borrowers assist in the financing of the property-such as when parents help their children buy a first home-this arrangement may not be used by non-occupant borrowers to develop a portfolio of rental properties. The degree of financial contribution by the non-occupant borrower, and the number of properties similarly owned, may indicate that an investor loan has become the practical reality and that, in effect, family members are acting as ''strawbuyers.''
FHA does not impose additional underwriting criteria on such transactions, such as specific qualifying ratios the occupying-borrower must meet individually, except as required for borrowers with non-traditional credit. Lenders must judge each transaction on its merits.

Handbook 4155.1: 2.B.3.b, 4.C.3.c