We're slowly trying to phase out long payment IDs, because they are (i) detrimental to user experience and (ii) privacy. Therefore, in CLI & GUI v0.14, it will be more difficult to make use of a long payment ID. You can, however, still use them (although, please ask your service to phase them out too). This is done as follows:

**In case you are using the GUI:**

1. Go to the `Settings` page of the GUI.

2. Go to the `Layout` tab. 

3. Check the `Enable transfer with payment ID (OBSOLETE)` box. 

You should now be able to utilize long payment IDs.

[![Monero payment IS setting][1]][1]

--------------

**In case you are using the CLI:**

Basically you have to launch the CLI with the `--long-payment-id-support` flag. This is done as follows:

**Windows:**

1. Close `monero-wallet-cli.exe` by typing `exit`

2. Make sure you are in the folder where `monero-wallet-cli.exe` is located.

3. Make sure your cursor is not on any of the files.

4. Right click, an option to open the command prompt should appear.

5. Now type -> `monero-wallet-cli.exe --long-payment-id-support`

**Linux:**

1. Close `monero-wallet-cli` by typing `exit`

2. Make sure you are in the folder where `monero-wallet-cli` is located.

3. Make sure your cursor is not on any of the files.

4. Right click, an option to open the terminal should appear.

5. Now type -> `./monero-wallet-cli --long-payment-id-support`

**Mac OS X**

1. Close `monero-wallet-cli` by typing `exit`

2. Check in which directory `monero-wallet-cli` v0.14 is located. An easy way of finding the full path of `monero-wallet-cli` is as follows ([source](https://superuser.com/questions/371513/how-to-tell-full-path-of-file-on-mac)):

>If you really want the full path to a file in a copyable form, you can drag and drop the file or its proxy icon onto a Terminal window. From there, you can then copy and paste it.

Thus, drag and subsequently drop `monero-wallet-cli` in the terminal and you should see its full path. 

3. Go to your desktop.

4. Open a new terminal (if don't know how to open a terminal, see [here](https://apple.stackexchange.com/a/256263)). 

5. Now type -> `cd full/path/to/monero-wallet-cli/directory`

6. For example, if `monero-wallet-cli` is located in say `~/Applications/Monero`, type:

    `cd ~/Applications/Monero`

7. Once the terminal is in the right directory (note that you can type `ls -a` to get a list of all files in the directory. If the list includes `monero-wallet-cli`, you are in the right directory). 

    `./monero-wallet-cli --long-payment-id-support`


  [1]: https://i.sstatic.net/sDVgj.png