@Grevieneiff68 What you can try at least for an Iphone:
You can also find out the SIM lock status of your iPhone using the IMEI number, which you can find in the settings under "Info". On MyimeiUnlock.com you can then use this number to check whether your iPhone is locked.
For Android: On IMEI.info
you can get a lot of information, including the simlock status, by entering the IMEI number of your mobile phone. You can find the IMEI of your Android mobile phone in the settings at the very bottom under "Info about device".