The description is confusing. Do you get three 12gb cards? As it says trio? Thanks

No, you do not get 3x 12gb cards. "Trio" refers to the fact that it is a Standard Size, Micro and Nano SIM card all in one - you just press out the size you need for your device.

Can this sim be topped up or should I buy two?

You can top it up with money, but you'll be charged at the non-plan rates for calls and texts. You can buy texts which don't seem to expire. 40 texts for 3 GBP. You can buy add on data, but you'll spend 25 GBP for 7 GB that EXPIRES IN 30 DAYS. So if you know you are going to use your data, buy 2 because the add on top up deal packages are NOWHERE as good as buying a new SIM with this data deal.

Will this sim card work in a mobile phone used just for data not for making calls?

I used 2x 12 Gb cards, in a smartphone, for 2 years, including in USA. Subsequently bought a 24Gb card which worked fine for a while then failed in USA. Had correspondence with 3-Mobile who said it was not for use in a phone. Conrtacted the supplier (7dayshop.com) whio said they use it in phones but subsequently confirmed via 3-mobile it was only for Tablets etc. so got a refund.

Does this have to be activated? And if so, how?

Once you use it for the first time, it is activated. I would recommend activating it in the UK or at least in Europe. The first one I bought, I used in the US for the first time and it took me hours to get it connecting.

ASIN	B01CMD4VKC
Best Sellers Rank	#209,400 in Cell Phones & Accessories ( See Top 100 in Cell Phones & Accessories ) #473 in Cell Phone SIM Cards
Customer Reviews	4.3 4.3 out of 5 stars (2,955)
Date First Available	March 23, 2016
Is Discontinued By Manufacturer	No
Item Weight	1.76 ounces
Item model number	3TDSIM12GB
Manufacturer	Three Mobile
Product Dimensions	3.54 x 2.83 x 0.79 inches

12GB Data SIM

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