An issuer can file an amendment to its offering statement to disclose changes, additions or updates to information on Form C/A for any offering that has not yet been completed or terminated.
An amendment is required for changes, additions or updates that are considered ‘material.’
The materiality determination is left up to the issuer based on the guidance that the SEC considers a material change to be a change that would affect an investor's investment decision. You may want to consult a lawyer to determine what constitutes a ‘material’ change for your Reg CF raise.
An issuer must reconfirm outstanding investment commitments within 5 business days following the filing of an amendment to Form C. Failure to do so will result in the investor’s commitment being considered cancelled.