For multiple births
Regulations: Art. 3 Text Recast of the legal provisions of the Autonomous Community of Extremadura regarding taxes transferred by the State, approved by Legislative Decree 1/2018, of April 10.
300 euros per child born in the tax period, provided that the minor lives with the parent on the date of tax accrual (normally, December 31) and there are multiple births.
Requirements and other conditions for the application of this deduction
The application of the deduction is conditional on the sum of the general and savings tax bases , boxes  and  of the declaration, does not exceed the following amounts:
When the children born live with both parents, the amount of the deduction will be prorated in equal parts in the declaration of each of them if they opt for individual taxation.