My husband and I will be in California for 8 days next month and would appreciate any recommendations for mobile data carriers. We live in England and have family in the US but whenever we go there, we purchase SIM cards from T-Mobile or other US carriers which never work! Sometimes we get phone and text and sometimes data floats in and out but we're tired of spending money on a service that doesn't deliver.

In the UK, I use O2 and my husband has Vodafone and we're now looking into using a UK carrier with a US element. We've also spoken to Three which seems to have a good, reasonably priced plan.

So I'd appreciate hearing from anyone who might have used these services successfully (we don't want to buy them and find there's limited coverage again). We're going to be in and around cities -- no offroading or remote areas.

Many thanks.

I don't have any inputs on UK carriers with US plans...

If you want to further explore US SIM options, the 1st question I'd ask is do you want data only access, or are you looking for a phone # / regular SIM/eSIM? I live here in the US so I've never tried to get a short term SIM. When I travel I get a data only esim from Airalo dot com. The advantage of an eSIM is you can install it at any time and don't need to open up a SIM slot on your phone... You'd need to check if your phone is eSIM compatible.

Unlike in Europe, VoIP options like using WhatsApp are not as prevalent - many, or most businesses still have a land line so if you want to be able to make calls you'll need either a phone # to call from, or a VoIP option that can call land lines. Personal use of WhatsApp is also not as widespread as it is in Europe. Some people use Facetime (apple), others use FB messenger, while many only use their phone # and SMS texting.

Airalo has a US option data only eSIM for very low price that looks like it utilizes TMobile & Verizon towers/network. There are only 3 co's in the US that own their own towers/network, those 2 along with AT&T. These days the cell coverage between the 3 is hard to distinguish - all are excellent in cities and towns, and along highways. Where they may vary is dead spots in certain neighborhoods, or dead spots in remote areas...

My own cell service is through Spectrum (spectrum dot com). They utilize the Verizon network and I get excellent service whereever I go here in the US, for a fraction of the price of Verizon. They may offer a short term esim - I don't know....

If you only need data, look at airalo. if you need a phone # SIM, maybe others will weigh in...

I’ve used Verizon Prepaid for years because I don’t want a contract & it’s the least expensive option they offer. Look on their website for the monthly price. I get a $10 discount for auto renewal so $35. so 1 month should be $45. Calls, texts & data included, much more than I ever use. The website will have the numbers. Simple, straightforward, reliable in my experience, not expensive. I’m in California. Verizon.com.

I use WhatsApp all the time in the US but of course only for personal calls to people who also have that app. You wouldn't use it for businesses. I've never had a problem using Tmobile anywhere in the US, so don't know what that's about. I do use a cheap prepaid plan with Tracfone, I think they use Verizon network, it works anywhere in US I've been. But I don't use the bring your own phone option so can't speak to that. I don't really use a phone that much, just for a few calls or texts. I do use some apps on it fine but never stream anything on it.

I currently use a Surfroam sim card for my local and worldwide service. It is different in that there is no voice component (however, I use Google Voice, a voip service with voice and text capabilities). I have been using this service for several years, on extended trips to Italy and Germany and locally in the USA. The data rates are roughly one euro cent per megabyte of data. As an example, in the past six months, my prepaid balance went from 94 USD to 77 USD with my normal usage. That works out to less than 3 dollars per month.

One caveat, your prepaid balance expires unless you recharge the balance within 12 months, and you can recharge with as little as 25 euro.

In the USA, surfroam uses AT&T and Verizon towers.

I highly recommend for a user who is not addicted to being on the phone all the time.

www.mysurfroam.com