On 30 November 2017, the Latvian Parliament agreed to ratify the protocol to income tax treaty with Singapore. The protocol was signed on 20 April 2017 to amend the income tax treaty of 1999. The protocol will enter into force once both parties have completed their internal ratification procedures.

The protocol will generally apply in Latvia from 1 January of the year following its entry into force. In Singapore, it will apply from 1 January of the year following its entry into force in respect of withholding taxes and for other taxes from 1 January of the second year following its entry into force.