QuickLinks -- Click here to rapidly navigate through this document

Exhibit 12.1

Tyco International Ltd.
Computation of Ratio of Earnings to Fixed Charges(1)
(dollars in millions)

	For The Six Months Ended
						Fiscal
	March 27, 2009			March 28, 2008
						2008		2007			2006		2005		2004
Earnings:
Income (loss) from continuing operations before incomes taxes, minority interest and cumulative effect of accounting changes	$	(2,258	)	$	838	$	1,431	$	(2,196	)	$	1,122	$	596	$	415
Add: Fixed charges		215			303		536		451			410		456		518
Less: Capitalized Interest		1			1		1		3			1		1		—
	$	(2,044	)	$	1,140	$	1,966	$	(1,748	)	$	1,531	$	1,051	$	933
Fixed Charges:
Interest expense before capitalized interest	$	152		$	232	$	397	$	313		$	280	$	322	$	377
Rentals		63			71		139		138			130		134		141
	$	215		$	303	$	536	$	451		$	410	$	456	$	518
Ratio of Earnings to Fixed Charges		—	(2)		3.76		3.67		—	(3)		3.73		2.30		1.80

(1)

The ratio of earnings to fixed charges is computed by dividing the sum of earnings before income taxes, minority interest and cumulative effect of accounting changes and fixed charges by fixed charges. Fixed charges represent interest expense (before interest is capitalized), amortization of debt premiums and discounts, capitalized expenses related to indebtedness and an appropriate interest factor on operating leases. Fixed charges represent amounts relating to continuing operations.

(2)

In the six months ended March 27, 2009, fixed charges exceeded earnings by $2,259 million.

(3)

In fiscal 2007, fixed charges exceeded earnings by $2,199 million.

QuickLinks

Exhibit 12.1

Tyco International Ltd. Computation of Ratio of Earnings to Fixed Charges(1) (dollars in millions)