Certifications. Professional certifications for mortgage underwriters often increase salaries by 5 percent to 10 percent. With an underwriting certificate, mortgage underwriters can earn $40,000 to $61,000 per year.The National Association of Mortgage Underwriters offers two certifications.s of 2012, mortgage underwriters are more likely to make between $38,000 and $55,000 per year, according to Robert Half Finance & Accounting, one of nation’s largest financial-recruitment agencies. Professional certifications for mortgage underwriters often increase salaries by 5 percent to 10 percent.