Then unfortunately a spousal visa is needed. The spouse will be issued a BRP - biometric residence permit - once they enter the country with their approved visa.
People with European citizenship can (until Brexit, if it happens) move via EEA rules and apply for a residence permit but that is a very different process, with a lot of uncertainty right now due to Brexit.
Do you have enough info on the different ways to meet the financial requirements of a spouse visa?
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