To be suspicious of this call?

[TheBananaStand2]

I just missed a call from a number I don’t know. I’m travelling on a train, that just went through a town that I don’t live in, and that, as far as I know, is not home to any people I know or services I use. The missed call was from a number with this town’s area code. I just noticed Bluetooth is on on my phone, which it isn’t, usually. AIBU to think that somehow my number got sent over the network as I passed through this town on the train, and now I’m getting spam calls? I googled the number: no results. They didn’t leave a message, either. Has this ever happened to anyone else?

Do NOT call the number .
Ignore it and if they call back and it’s important then they’ll leave a message

As for the blue tooth thing , god knows ..
I have mine on all the time as it connects to my iwatch and my car and I rarely get spam calls

Your phone number doesn't go out on the network... you have a sort of 'secret' number called your IMSI (international mobile subscriber identity) that the network uses to call you. When someone calls your number, the network looks up that number and cross references it to your IMSI and calls that (it's a little more complex than that, but that's the basics of it) - That's how you can change number without having to change SIM card. The IMSI is related to your SIM. On top of that, your handset also has a unique ID, called an IMEI (International Mobile Equipment Identifier).

Bluetooth doesn't make calls or give out your number per se. It allows two or more devices to 'pair' with each other - then once paired, these can trigger your handset to make a call (but it's your handset making the call).

IF you pair some devices with your phone, they will ask for extra permissions to read info from your phone - like call logs and address book, but this can only happen once you've paired them and granted permission.

One way bluetooth 'could' (theoretically) give away your number is if a rogue application changed your bluetooth ID (name) to your phone number, but on a modern handset, that requires special permissions for the application, and you'd be able to see it when you look at your bluetooth settings (check the name).

But all this is paranoia - it's far more likely to just be coincidence.

Are we 100% sure it was a genuine phone call as opposed to a Whatsapp (or similar) call? they can look very similar on some devices.

I think I have read about similar reports at whycall.me few weeks ago. If they bother you too much, I think you can try to call them back and confirm who's calling and what they want from you. If you're unsure, then just block the number.

As others have said... do not call back.
Calling back can cost silly money, and you're also signalling to them that you are responsive, so likely to be put on a higher priority list to be pestered further.
As a side note... never open spam emails and set your default to 'don't download graphics', as this is a similar way to determine if your email address is actively in use.

They've always been able to mimic a local code.
It means nothing, and is absolutely no indication of their real location.

But how would a local dial code work cold call on a mobile?

It works (on some people) because a local code feels more reassuring just like it would on a landline.
If they have your mobile number and a reasonable clue of where you are located (normally) they'll use that local area code.
So if they know you're Mrs Smith, and usually in the Manchester area, then it's worth mimicking an 0161 number to your phone in the hope you might pick up thinking it might be some local service, or acquaintance etc.

I've had ppi or injury calls that appear to come from a local number.

It's to make you more likely to answer the call than a completely unknown number.

I answer the call, ask them their location abd then tell than that any company that uses such shady practices will never get me to engage with them.

But I'm a fucker.

They also masquerade as mobile numbers, it used to be they were usually 020 numbers but they are quite crafty now