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Check on this site <https://www.frequencycheck.com/brands/sony?utf8=%E2%9C%93&q[full_name_cont]=z3+compact&commit=Search>
You can check by phone model / country / carrier.
In France if you are a "Free Telecom" subscriber either D5803 or D5833 will to the same as "Free" uses ONLY ONE LTE band the LTE B7(2600) band <https://www.frequencycheck.com/bands/lte-band-7-2600>
But it would be a pity if you suscribed to another carrier which exploits 2 or 3 LTE bands (B3, B7 and B20), so in France best is D5803.
In Australia it would be D5833 <https://www.frequencycheck.com/country-compatibility/jvg8y/australia/devices?utf8=%E2%9C%93&q[full_n...>