Certificate of Tax Residence for Greek authorities

I've went through the process of issuing a certificate of tax residence through HMRC, but since I do no have any income to declare from Greece to the UK, I receive a Letter of Confirmation instead. Despite the letter mentioning that this should be accepted from the Greek authorities, apparently this is not the case. They still claim that they need a proper certificate. Is there any update on that from the HMRC? Can I somehow enforce a Certificate of Tax Residence to be issued via my application? Thanks in advance.

Hi,
A certificate is only applicable when foreign income is received. 
If the Greek authorities will not accept the letter of confirmation, you will need to return this along with their rejection letter for an appropriate response to be issued.
Thank you.

Thanks for the reply. I have received income from Greece within the financial year of 2023 but before I moved to the UK. The greek authorities need the tax certificate from the time I started working in the UK till the end of 2023. Does that count as foreign income for the HMRC? Should the Letter of confirmation be still ok for my case? Thank you very much in advance!

Hi,
No as it is before you came to the UK.
A letter of confirmation would then apply and should be accepted by the Greek authorities.
Thank you.