The Washington state self employment tax covers both Social Security and Medicare payments when you're a solo worker. The total is 15.3%, with 12.4% covering the part of Social Security and 2.9% covering your Medicare.
The Washington state self employment tax is decided on year by year basis. In 2020, the Social Security percentage will be applied to the first $137,700 of your earnings. Medicare is applied to everything you earn. Those who file as a married couple will face differences, for instance you will have to pay for your spouse if he/she works for you.
The Washington state self employment tax requires quarterly payments made on the following dates:
Read our guide on how to file quarterly estimated taxes.
Washington state self employment tax federal requirement is Form 1040-ES, Estimated Tax for Individuals. Be prepared to fill it in.