Employment history requirements for investment property

[Karene Burnett]

My Husband and I have been looking to purchase our first investment property. My husband has been at his current job for 7 years and it is a 70/30 split Salary/commission. He was offered a position at a new company with a salary higher than his current total expected earnings and is planning on taking it. After starting a new position how long should we wait before applying for a loan? Just looking for typical work history requirements. His income will be guaranteed now. Would 30 days with a letter from his new employer confirming his salary be sufficient? What is the typical timeline? Any help is appreciated. Thanks!