IP Address Restrictions is a feature to restrict users of the services using source IP addresses.
For example, you can allow the use of Kintone only to the IP addresses of your company to prohibit unauthorized access from third parties.

If you want to allow access from remote locations during business trips or the remote workplace outside the office, consider enabling two-factor authentication.
If IP Address Restrictions Does Not Meet Your Need

• Kintone Users & System Administrator

For details, refer to "Types of Administrators".

1. Click in the header.

2. Click Users & System Administration.
   Accessing Kintone Users & System Administration

3. Click Access Control.
   

4. Click "Allow specific IP addresses".
   By default, "Allow all" is selected.

5. Allow access from specific IP addresses.
   In the "IP Address" field, enter the global IP addresses in IPv4 format. The IPv6 format is not supported.
   You can specify up to 1,000 IP addresses.
   If you want to allow access from multiple IP addresses using CIDR notation, enter the prefix in the "CIDR" field.

6. Click Save.
   It may take some time until the settings are applied.
   Once the configuration completes, an e-mail is sent to the e-mail address of the administrator.

If You made a mistake on setting IP Address Restrictions and lost access to Kintone, try one of the followings:

• Click "Reset URL" in the e-mail you received when the setting was completed.
  This Reset URL expires after one hour.
• Use Contact Us link to make an inquiry.

In the following cases, it is hard to block unauthorized access from third parties with IP Address Restrictions.

• When you use Kintone on your smartphone, or your source IP address changes dynamically (due to remote work, for example)
• When you access from the IP address shared by many other anonymous users (shared office, public wireless LAN, for example)

Consider using two-factor authentication.
For details, refer to the following page:
Using Two-Factor Authentication