Exhibit 16.1 [Letterhead of Deloitte & Touche LLP, Atlanta, Georgia] April 7, 1999 Securities and Exchange Commission Mail Stop 9-5 450 5th Street, N.W. Washington, D.C. 20549 Dear Sirs/Madams: We have read and agree with the comments in Item 4 of Form 8-K of Numerex Corp. dated April 7, 1999. Yours truly, /s/ DELOITTE & TOUCHE LLP - -------------------------