Yes, April does have some tax filing restrictions/disqualifications that will prevent tax filers who meet certain criteria from being able to file through.
Situations not supported by April:
Section 1256 options and futures contracts
Certain tax treatments for professional day traders
Foreign income
Foreign addresses
Non-resident returns
Taxpayers under the age 18 as of December 31, 2025
Individuals with ITINs or ATINs
Taxable refunds reported on Form 1099-G
Adoption credits
Multiple state filing
If you fall into any of these categories, then tax filing through April is not possible. That said, you can still download your Tax Reports to use when filing with a different filing software or tax preparer.