Bank Credit Line	3 Months Ended	12 Months Ended
Mar. 31, 2013	Dec. 31, 2012
Notes to Financial Statements
Bank Credit Line	(8) Bank Credit Lines On April 10, 2012 Zoom Telephonics, Inc. entered into a Loan and Security Agreement with Silicon Valley Bank (the “Loan Agreement”). This Loan Agreement was filed with the SEC in an 8-K dated April 13, 2012. The Loan Agreement provided for up to $1 million of revolving credit, subject to a borrowing base formula and other terms and conditions as specified in the Loan Agreement. The Loan Agreement had a one year term which was set to expire April 9, 2013. Borrowings were secured by all of Zoom’s assets including Zoom’s intellectual property. Zoom terminated this loan with payment in full on December 19, 2012 in connection with a financing agreement with Rosenthal & Rosenthal. On December 18, 2012, Zoom Telephonics, Inc. (“Zoom”) entered into a Financing Agreement with Rosenthal & Rosenthal, Inc. (the “Financing Agreement”). This Financing Agreement was filed with the SEC in an 8-K dated December 21, 2012. The Financing Agreement provides for up to $1.75 million of revolving credit, subject to a borrowing base formula and other terms and conditions as specified in the Financing Agreement. The Financing Agreement has a two year term. Borrowings are secured by all of Zoom’s assets including Zoom’s intellectual property. The Financing Agreement contained several covenants, including a requirement that we maintain specific levels of tangible net worth and working capital. On March 31, 2013 Zoom was in compliance with the covenants of the Financing Agreement with Rosenthal & Rosenthal, Inc.	On April 10, 2012 Zoom Telephonics, Inc. entered into a Loan and Security Agreement with Silicon Valley Bank (the “Loan Agreement”). This Loan Agreement was filed with the SEC in an 8-K dated April 13, 2012. The Loan Agreement provides for up to $1 million of revolving credit, subject to a borrowing base formula and other terms and conditions as specified in the Loan Agreement. The Company’s most recent charge for the month of September was an annualized interest rate of 11.125%, but this may change (or decrease) depending on Zoom’s balance sheet as specified in the Loan Agreement. Our outstanding bank debt at September 30, 2012 was $796,000. The Loan Agreement has a one year term which expires April 9, 2013. Borrowings are secured by all of Zoom’s assets including Zoom’s intellectual property. The Loan Agreement contains several covenants, including a requirement that Zoom maintain a tangible net worth of at least $3.0 million. On December 18, 2012, we entered into a Financing Agreement with Rosenthal & Rosenthal, Inc. (the “Financing Agreement”). The Financing Agreement provides for up to $1.75 million of revolving credit, subject to a borrowing base formula and other terms and conditions as specified in the Financing Agreement. The Financing Agreement has a two year term. Borrowings are secured by all of our assets including our intellectual property. The Loan Agreement contained several covenants, including a requirement that we maintain a tangible net worth not less than $2.5 million and working capital not less than $2.5 million. We used a portion of the proceeds from the financing arrangement with Rosenthal & Rosenthal, Inc. to pay off our existing loan of $879,047 with Silicon Valley Bank. On December 19, 2012, the Loan Agreement with Silicon Valley Bank was terminated upon payment in full by us of all amounts owed under such agreement

Bank Credit Line

3 Months Ended

12 Months Ended

Mar. 31, 2013

Dec. 31, 2012

(8) Bank Credit Lines

On April 10, 2012 Zoom Telephonics, Inc. entered into a Loan and Security Agreement with Silicon Valley Bank (the “Loan Agreement”). This Loan Agreement was filed with the SEC in an 8-K dated April 13, 2012. The Loan Agreement provided for up to $1 million of revolving credit, subject to a borrowing base formula and other terms and conditions as specified in the Loan Agreement. The Loan Agreement had a one year term which was set to expire April 9, 2013. Borrowings were secured by all of Zoom’s assets including Zoom’s intellectual property. Zoom terminated this loan with payment in full on December 19, 2012 in connection with a financing agreement with Rosenthal & Rosenthal.

On December 18, 2012, Zoom Telephonics, Inc. (“Zoom”) entered into a Financing Agreement with Rosenthal & Rosenthal, Inc. (the “Financing Agreement”). This Financing Agreement was filed with the SEC in an 8-K dated December 21, 2012. The Financing Agreement provides for up to $1.75 million of revolving credit, subject to a borrowing base formula and other terms and conditions as specified in the Financing Agreement. The Financing Agreement has a two year term. Borrowings are secured by all of Zoom’s assets including Zoom’s intellectual property. The Financing Agreement contained several covenants, including a requirement that we maintain specific levels of tangible net worth and working capital.

On March 31, 2013 Zoom was in compliance with the covenants of the Financing Agreement with Rosenthal & Rosenthal, Inc.

On April 10, 2012 Zoom Telephonics, Inc. entered into a Loan and Security Agreement with Silicon Valley Bank (the “Loan Agreement”). This Loan Agreement was filed with the SEC in an 8-K dated April 13, 2012. The Loan Agreement provides for up to $1 million of revolving credit, subject to a borrowing base formula and other terms and conditions as specified in the Loan Agreement. The Company’s most recent charge for the month of September was an annualized interest rate of 11.125%, but this may change (or decrease) depending on Zoom’s balance sheet as specified in the Loan Agreement. Our outstanding bank debt at September 30, 2012 was $796,000. The Loan Agreement has a one year term which expires April 9, 2013. Borrowings are secured by all of Zoom’s assets including Zoom’s intellectual property. The Loan Agreement contains several covenants, including a requirement that Zoom maintain a tangible net worth of at least $3.0 million.

On December 18, 2012, we entered into a Financing Agreement with Rosenthal & Rosenthal, Inc. (the “Financing Agreement”). The Financing Agreement provides for up to $1.75 million of revolving credit, subject to a borrowing base formula and other terms and conditions as specified in the Financing Agreement. The Financing Agreement has a two year term. Borrowings are secured by all of our assets including our intellectual property. The Loan Agreement contained several covenants, including a requirement that we maintain a tangible net worth not less than $2.5 million and working capital not less than $2.5 million.

We used a portion of the proceeds from the financing arrangement with Rosenthal & Rosenthal, Inc. to pay off our existing loan of $879,047 with Silicon Valley Bank. On December 19, 2012, the Loan Agreement with Silicon Valley Bank was terminated upon payment in full by us of all amounts owed under such agreement