Hi @hobbysellebayer, good question. Even though you are filing jointly, the SE applies to the self-employment income only, so the best rule of thumb is to base your calculation on the SE income only. The instruction in line 9 of the form also guide each taxpayer to file separate forms to calculate the tax correctly, so hypothetically, if both you and your spouse were self-employed you would need to fill out separate 1040-ESs to calculate the tax, so it would be a good assumption that the $1000 applies solely to the SE income.
