• Tax Return Filing in the face of Passbook Portal problems

Dear Experts,
My employment duration with a certain past employer spanned over the latter part of FY 2016-17 and the earlier part of FY 2017-18. The old tax regime was prevalent then. I made PF contributions in that employment and presumably received tax benefit u/s 80C. 

Around Nov 2025, I got my PF contribution with the aforementioned employer transferred to my latest PF membership account, and then got the entire PF corpus withdrawn in Jan 2026. 

For the past few years I have had an active GST registration and have been filing ITR-3 under the new tax regime. Since I have income from PF withdrawal in FY2025-26, in the ITR-3 form this year, I am required to enter assessment year-wise details of PF contributions made in past years corresponding to the withdrawn PF amount, so that the 80C tax benefit availed in earlier years under the old tax regime can be reversed.

However, I am a facing a problem because the PF passbook portal is not showing the passbook entries for years before 2024 due to their ongoing technology upgrade. I can see the total PF amount transferred from that employer including the employer contribution, employee contribution and interest parts. However, I am unable to know the division between FY2016-17 and FY2017-18 contributions in the absence of availability of prior year's PF passbook entries on the portal. I am not even sure if it includes any PF amount transferred in from a still earlier employer (from before 2016), or if it includes any VPF contributions. Unfortunately, I also do not have access to any of the salary slips from this employer. I have been waiting for the Passbook portal to return to full functionality but there seems to be no sign of it happening. 

My question is: 
Given that accurate information is not available from the passbook portal, is it ok if I divide the amount contributed (both employee and employer contributions) across the two FY's in proportion to the days or months spent in employment with that employer in each of the two FY's? 

Please let me know if this approximate method (including implicit presumptions) would be acceptable under the circumstances. For further context, my net taxable income in FY25-26 will remain well under 12L even after including the said past PF contributions, so the net tax payable should remain zero (with the applicable rebate) regardless of the exact actual distribution of contributions across the two FY's. 

Thanks a lot. I look forward to receiving your answer and understanding the important considerations.

PS: I do have access to past year's ITR returns but because of certain complexities (such as other 80C heads with unknown amounts) those are not very useful in this scenario.