If you are all set to do apply for unmarried partner visa in UK, you have to make sure that everything has been taken into consideration. You have to make sure that your intention to remain in UK will be granted and you can do this by repeatedly reviewing your attachments on your visa application.
If not properly scanned and reviewed before submitting, there could be some mistakes that may affect your request. Take a look on the requirements and check versus yours (and for your partner as well.) This would save you not only money but time as well.

Check if you have the bank certification and your University certificate. You can’t forget these documents or else you’ll go back to step one. All enclosed documents must have both supporting documents from you and your partner. This way, you’ll be able to prepare additional documents needed before sending them out.

After confirming that you have all the documents needed, you must then decide on how to submit to the visa consulate. You can either submit it via post or by hand it personally to their office. If you are applying via mail, you have to make sure that you’ll be ready anytime they call you for a personal interview.

Most likely since you are applying as unmarried partner, you have to attend the visa interview together with your partner. Somehow it would be better if you call the consulate visa office to submit your papers and to ask for an appointment the same to save your day and to save money, too.