Indian bank interest

Hello I am a resident UK national, currently my earnings are within the personal tax threshold, I also complete in self-assessment for a small amount of sole trader income and bank interest My family has gifted me money in India and the money is residing in a bank account over there. The funds are in fixed deposit that are due to mature in this UK tax year. I was told I can avoid having to pay the 15% tax on interest (charged by Indian authorities on remitting/repatriating funds to UK) if I provide a HMRC Certificate of Residence to the tax authorities in India, and thereby avoid having to claim it back here. I sent a request to HMRC but received a letter back with a "Letter of Confirmation", stating that I could not get a Certificate of Residence as I currently have no income from overseas to declare to HMRC - I will do, just have not received the interest yet and have not filed a self-assessment for this year yet. Can you please advise what the best course of action is? Currently, even with the projected Indian bank interest I would still stay within my personal tax threshold. If I claim the 15% credit relief from you (once I have paid it in India) will I receive it in full even though I have not paid any tax? Thank you

Hi
As previously advised, HMRC is unable to provide a Certificate of Residence to an individual who is not in receipt of income from overseas.
If the tax authorities of India will not accept your 'Letter of Confirmation of residence' , you would have to re-apply for a Certificate of Residence when the Indian interest has been received.                  
UK residents with foreign income or gains: certificates of residence