Spouse Visa Extension - NARIC assessment required?

[johnnyclever]

Dear Members

Seasons greetings to one and all. I'm in a bit of a conundrum re NARIC assessment so would really appreciate if someone can help. My wife came to the UK from India (not majority English speaking country) on a spouse visa in April 2016. When the application was made we submitted her degree certificate and a letter from her university confirming the course was taught in English. She was granted a visa.
I'm now applying for an extension and was wondering if I need to do a NARIC assessment? Page 17 of the guidance here (https://assets.publishing.service.gov.u ... 3.0ext.pdf) says the applicant need not provide further evidence of her qualification but the online application form says otherwise.
Do I really need to do a NARIC assessment or should I just mention in a covering letter that the applicant previously satisfied english language requirement and point to the official guidance?

Apologies if this is a repeat question, I've searched the forum but couldnt find an answer.