You’ll get a decision on your visa within 12 weeks when you apply from outside the UK. It takes 8 weeks for the processing when you apply from inside the UK.
If you apply for super priority decision while applying for UK dependent visa, your decision will be as follows:
Your application will be processed and decided within 1 working day if you take an appointment on weekdays.
If your appointment is on a weekend, your decision will be disclosed in 2 working days.
If your details are not correct, then it may take longer. For example:
Minimum income requirement is not met
A personal interview is needed
English requirements are not fulfilled by you
Don’t meet all requirements
A person with a criminal record