Samsung Galaxy A10
Notes from a customer getting our SIMs to work with this handset:
The Samsung Galaxy A10 retails at Carphone Warehouse for around £139 It is an Android 9 device, which dual SIM capability. It requires nano-SIM size cards, which may require some work with cutters to make A&A SIMs fit.
There is a warning on the box "European SIM cards only".
The phone does not recognise A&A SIMs as European SIMs and requires an unlock code to turn off the regional locking 'feature', which is built into the phone. This process is not required if the phone is activated with a SIM that it does recognise.
This region lock is NOT a network lock (as the phone is sold SIM-free). Some networks are not selling handsets locked to specific networks any more, although BT and Vodaphone still are. This may change following this announcement from OFCOM https://www.ofcom.org.uk/about-ofcom/latest/media/media-releases/2019/ban-on-mobile-firms-selling-locked-phones
There is a leaflet inside the box which goes into some detail in 26 different languages, the english section of which reads:
European model. THis product should be activated with a SIM card issued by a mobile operator within Europe (as defined EU/EEA, Switzerland, and the following Non-EEA countries: Albania, Andorra, Bosnia and Herzegovena, Former Yugoslav republic of Macedonia, Monaco, Montenegro, San Marion, Serbia and Vatican City). To use SIM cards from other regions, a cumulative call of five minutes must first be made with the SIM card from European operators. If a SIM card issued from another region is used for activation, the phone may not work. In this case, the device will need to be released at the nearest Samsung service center.
The practical upshot of this is that with only an A&A SIM card installed, the phone will prompt for a PIN number (which is not any PIN number that may associated with the SIM), but will allow you to use the device over WiFi, but will not recognise the SIM. No calls or mobile data, incoming or outgoing will be possible, as the phone will not attempt to register the SIM with the network.
In my case, I worked around this by buying an EE SIM from the local newsagent (for a massive £1). I have not registered this SIM (doing so requires creating an account online and adding credit), but out of the packet it works for incoming calls. With this SIM present, the phone does register itself, and does also activate the A&A SIM card which I moved to slot 2.
Other minor gotchas with this phone. Install the SIM card and SD card contact face downwards, and slide into the phone with screen upwards (otherwise, the not very well designed SIM carrier will go in, but get stuck and will require some effort to remove, causing cosmetic damage)