I need to get the sum of numbers in a column if they have a certain criteria in common in another common.

For example:

Zip Code Amount
11111 200
11111 300
55555 100
11111 100
55555 50

If the zip code is the same I need the sum of the amount, so for zip code 11111 it would be 600 and for zip code 55555 it would be 150.

Thanks and God bless in advance for the help!