Can you file taxes after the deadline?

Absolutely. In fact you must. Sooner the better obviously, but, late filing isn't even penalized that badly (if at all if you have a reasonable cause excuse), and frequently your doing so will get a refund that you had coming, (filing is different than paying). Note: Since the statute of limitations(the laws about how long you can be audited and assessed for mis-reporting), starts running with the filing of the return, unless you file a return your ALWAYS liable for it. So apply for something from the govt., like social security or such, even years from now...have the computer see a missing filing...get a bill...with all penalties, interests, etc...not that unlikely.