Today, Mytour will guide you on how to allow someone you previously blocked to contact you via Facebook Messenger.
Steps
On iPhone and iPad

Open the Messenger app with the lightning bolt icon in the blue chat box.

Click on your profile icon, represented by a blue person icon in the top left corner of the screen.

Tap on the People (Contacts) listed below Notifications (Alerts).

Click on Blocked (Blocked Contacts). This section is usually located at the bottom.

Click on the name of the person you wish to unblock.

Slide the "Block Messages" (Block messages) toggle to the Off position. The switch will turn white. Now, you will be able to communicate with this person and vice versa.
On Android

Launch the Messenger app with the lightning bolt icon located inside the blue chat box.

Tap on the profile icon with the gray person image in the top right corner of the screen.

Scroll down and select People (Everyone) located just below the SMS section.

Tap on Blocked People (Blocked Contacts). This option is usually the last one in the list.

Click on the Unblock action next to the user's name.

Click on Unblock on Messenger (Unblock on Messenger). This is the first option listed. From now on, you and this person will be able to message each other via Facebook Messenger.
On a computer

Visit www.facebook.com using your browser.
- Log in to your Facebook account (if necessary).

Click on the ↓ icon in the top right corner of the screen.

Select the Settings option, which is located towards the lower end of the options menu.

Click on Blocking found in the upper section of the left-side options list on the page.

Scroll down to the 'Block Messages' section. Below this, you'll see a list of users you've blocked from contacting you via Messenger.

Click the Unblock button next to that person's name. Make sure this person is listed under the Block messages from section. From now on, you and this person will be able to communicate through Facebook Messenger.
