How Can I (Cheaply) Ensure My UK Phone Number Is Not Reassigned Whilst Living Abroad?

[Perry2]

Hello all, 

I hope someone here might have the knowledge help me.

I am currently in the UK and have an o2 pay-as-you go sim card. I am about to spend an extended period in Singapore - perhaps for a year or more. However, I do not wish to lose my UK number, and would like to be able to use my sim card when back in the UK, such as when briefly visiting. 

I have heard conflicting information about how quickly my sim card will expire through inactivity and risk my phone number being reassigned to someone else. I have heard claims ranging from: I can keep my sim card active simply by making any chargeable transaction (e.g. a text) every 6 month, - to someone else saying that I must top-up my credit every 2 months.

So what's the truth here? I've looked and been unable to find any official written information about this. I'd like to avoid paying excessively whilst out of the country to keep my number.

Any help is greatly appreciated

Thank you

[Anonymous]

Well I don't think it can be dependent on making a call anyway, because if you have a PAYG SIM and pay for a bundle every month you might not ever make a call at all. Thus meaning you would lose your number through inactivity after 6 months for not making a chargeable call. 

[MI5]

It's not solely making a call.

If you don't make a call you have to top up every 6 months.

[Anonymous]

Yes but the crux of the question is when the time limit of 6 months starts to countdown, that was the actual question. Imo it would be from the first day after last day of the last bundle you paid for, as you have paid in advance for one month (28, 29, 30, or 31 days) So in effect you are paying for a service on that last day.

[MI5]

But then it would be 7 months since you "topped up"

[Anonymous]

Not necessarily, you could have topped up 3 months before that with enough to pay for 3 months bundles. 

You might not even top up for a year if you have enough credit. 

[Perry2]

Thank you very much again everyone, that was really helpful @Bambino @MI5 @Anonymous 😊