Tier 2 Dependent - Visa expiry date of main applicant

[aounarts]

Hi all,

I am new to this forum. I have a question regarding IHS for the tier 2 dependent application of my wife.

I have already applied as a main tier-2 general visa applicant a few months back and probably get my passport back in a few days and will travel towards the end of this month.

Now I would like to complete my wife's application (tier 2 dependent) as I came to know that from October the IHS fee will increase considerably. I have complete her application until the IHS payment "Summary" page, where it is asking to enter the visa expiry date of the main applicant.
What should I enter here? since I haven't received my passport yet. Plus even if I receive my passport, from my understanding it will only have a temporary visa vignette and my actual visa expiry date will be on my BRP card.
So how you should I proceed to save myself from paying the extra IHS fee after this month?

[CR001]

It is the length if visa you applied for based on your cos.

[aounarts]

Due to COVID-19 my joining date is getting delayed as well.
I am not sure as to should I re-calculate my visa expiry date from the latest tentative joining date?
Or should I put the visa expiry date as per my application, which was applied way back in April?

[CR001]

Your visa expiry date is relevant only to your cos duration and visa you applied for. Your joining date is irrelevant to the full validity of your visa.