JBSE qualified and backdated, Which backdate is best?

I hope the thread title is not confusing, but I struggled to come up with a more descriptive title.
I left employment in Nov 2024 and sold my shares to remaining partners. All was wrapped up in Dec 2024.
I applied for JB but there were a couple of mix-ups and Xmas interruptions during the application period. That's sorted now and I've been approved for JBSE for 234 days. See the screenshot of the situation.
I'm not sure which is best for me. Is JBSE taxed with total income ( spouse still working with high salary)? Also, what happens with prsi contributions. I have 48 in 2024 and ultimately I'll fall short ( by about 172 of the total amount needed for pension at age 66, that's including credit for jbse time and subsequent signing on for credits.
Which backdate is more advantageous to me, or does it matter?

I am assuming that you were paying class S Prsi.

Because you stated that you have 48 contributions for 2024, I presume you were a paid director.

Class S for a paid director is deducted under the PAYE system.
This operates the same as for an ARF. A person with an ARF who has a minimum of 5k per year will gain 52 class S regardless of the number of monthly drawdowns.

Because of this, provided that your 2024 earnings are over 5k, you should get 52 class S contributions for 2024. These 52 contributions will show on your Prsi record in 2025. (They might be currently showing.)

If you opt for your JBSE claim to start on 21st January, you would only lose 3 Prsi credits, but you gain an extra 7 weeks of JB payments.

JBSE is subject to income tax as if it was earned income. (except for the first 13 euro per week)
The income tax is not deducted under the PAYE system.
The tax is taken by reducing your tax credits and 20% tax band.

If you have no other earnings for 2025 you could get your JB tax free because your non transferable earned income credits would cancel out the income tax.

Provided that you have at least I class A contribution on your Prsi record you will get Jobseekers credits during your JB payments period, and beyond this if you continue to sign on, you will get credits up to age 66.

At age 66 you could decide to defer your COAP up to maximum age 70. If you do this you can gain extra Prsi contributions.
Jobseekers credits are not granted beyond age 66, but Prsi is possible for employment, ARF drawdowns or for voluntary Prsi payments up to COAP claim date or maximum age 70.

You would need to calculate if it is financially worthwhile to defer.

Excellent explanation. Thanks a lot @S class.
All your assumptions correct and, yes , I can see 52 contributions credited for 2024 when I review that statement online. I will opt to have the backdate of Jan 21st. selected. I don't expect to have any additional employment income this year. I'll consider what to do @ 66 when , and if, I get there.
Thanks again