We have had several clients receive letters from the IRS about the amount they received from their stimulus checks. 

The first step is to compare what was reported to the IRS through the tax return to the amount the IRS reports they sent. 

This is how you check the records on IRS.gov:

https://sa.www4.irs.gov/eauth/pub/login.jsp?Data=VGFyZ2V0TG9BPUY%253D&TYPE=33554433&REALMOID=06-00029c6a-0543-17b0-89b8-163b0acf40c7&GUID=&SMAUTHREASON=0&METHOD=GET&SMAGENTNAME=UOkC7yx4eMTO24FGxPfBRb5q3Mj3Xh3pyXfBEjYyHJ97nGCXu16wx5MzFHjfZmlG&TARGET=-SM-HTTPS%3a%2f%2fsa%2ewww4%2eirs%2egov%2fola%2ftax_records%3fGMP%3d1