No, not a USPS office. We filed our application at a City of Seattle Customer Service Center. Yes, our applications were submitted together. They also accepted just one original marriage certificate for both children’s applications.
Thank you.
Just to update this - we put in our passport application and this is correct. We submitted both parent’s certificates of naturalization plus photocopies. We were able to submit both parents and children’s application together with only the two certificates.
My husband and I have just naturalized. We want to apply quickly for our passports as processing is taking so long and we hope to travel internationally in December. We have two minor children who met all the requirements to naturalize at the same time as us. We are trying to figure out if we can apply for their passports at the same time. The issue is that we just have our two Certificates of Naturalization and need to do four applications. Is there any type of family application or way of using the same document to submit two applications together? If not, is the only option really to wait until my husband and I get our passports (probably months) and then apply for the kids? Has anyone been in a similar situation and found a solution?