Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Aug. 12, 2020
Cover [Abstract]
Entity Registrant Name	Zoom Telephonics, Inc.
Entity Central Index Key	0001467761
Document Type	10-Q/A
Document Period End Date	Jun. 30, 2020
Amendment Flag	true
Amendment Description	This Amendment No. 1 to the quarterly report on Form 10-Q for the period ended June 30, 2020, filed with the Securities and Exchange Commission on August 13, 2020 (the “Original Filing”), is being filed solely for the purpose of correcting an error reflected in Note 4(b) to the Notes to Condensed Consolidated Financial Statements contained in Item 1 of the Form 10-Q that relates to the minimum annual royalty payment outstanding for the remainder of 2020. No other changes have been made to the Original Filing.
Current Fiscal Year End Date	--12-31
Is Entity's Reporting Status Current?	Yes
Entity Filer Category	Non-accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Shell Company	false
Entity Interactive Data Current	Yes
Entity Incorporation State Country Code	DE
Entity File Number	0-53722
Entity Common Stock, Shares Outstanding		23,891,142
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2020