Yeah, I know someone who had a similar experience. When he moved to the US, his employer (McAfee) offered to cover a big tax firm for his filing as part of the relocation package (same employer, just a country transfer). Pretty sure it was PwC. You’d think that would guarantee a smooth process, but according to him, they did a really poor job.

The proposal they put together missed several deductions he qualified for, ignored a lot of info he had sent, and was full of basic mistakes.

In the end, he scrapped their work and filed everything himself. I asked if the IRS ever came back to him about it... so far, no issues.