Generally, your gains from such employment overseas will not be taxed in the foreign country if:
(i) There is a Double Taxation Agreement (DTA) between Singapore and the foreign country; or
(ii) There is a provision for reciprocal exemption by Singapore and foreign governments.
Should the gains from your employment be taxed in the foreign country, you may apply for double taxation relief or tax remission in Singapore, to avoid being taxed twice on the same income.
Please approach your employer for clarification on application for tax remission for Overseas Cost of Living Allowances (OCLA).