Using a phone SIM in a tablet

[MoAbbasi]

Hi there,

I have ordered myself an Ipad Pro 12.9 with cellular from work. I want to use the cellular by using an o2 contract 

My question is, would I be able to use my phone SIM in the iPad at times I might need it. (I carry a SIM tool and would probably use it on long train journeys.) 

Aside from that, o2 has a January deal for 250gb data. I'm interested in this plan, but unsure if I can pop it in my iPad 

The tablet deals are awful, they want the same price for a mere 10GB. I could very easily use a backup phone for hotspot and it would be leagues cheaper. 

I don't think I'd bother buying a SIM for tablet unless I could get a reasonable amount of data for a reasonable price. So does this work?

[MI5 · Accepted solution]

@MoAbbasi 

It will work for occasional use but if you use it all the time, O2 will block the sim as you need the specific tablet sim for an iPad.