Patent royalty deduction: resident patentees may claim a capped deduction for royalty income subject to certification and remittance conditions. An individual resident patentee may claim a deduction for royalty income from patents registered on or after 1 April 2003 equal to the whole royalty or a prescribed monetary cap, whichever is less. Royalties under a compulsory licence are capped at amounts fixed by the Controller. Foreign-sourced royalties qualify only if remitted in convertible foreign exchange within six months (or an authorized extended period), and prescribed certificates must be furnished with the return; the same royalty income cannot be deducted under any other provision once this deduction is claimed.