We made modifications to how signers are authenticated when the SMS authentication configuration is enabled by senders in Box Sign.
Previously, when SMS authentication was enabled, signers were not prompted to authenticate themselves until the end of a signature request when they completed all the required fields assigned to them. We modified the signer authentication workflow to require signers to authenticate themselves via SMS authentication before they gain access to view, fill, and sign the signature request. This modification aligns with industry standards and other signer authentication workflows within Box Sign like Box account login and password authentication.
To learn more, see Additional Recipient Authentication in Box Sign.