Tax Declaration for Land Ownership

we've been paying our land's tax declaration since 1985, then all of a sudden there is this relative of our ancestor who owned the land who's claiming ownership of it. we need a legal advise on what can we do to secure our right since we're the ones who's paying land tax for the longest time. Thank you!

I asume the land isn't titled, because IF it's titled and you have it in YOUR name, then that's proof enough.

NOTE! I'm not sure if the part before the " .." are still valid after the part after the ".." started.

Paying tax at a property is NOT FULL proof, but useful as HINTS who is owner.
(Some SCAMERS pay tax at property they DON'T own, and then they use the tax documents to fool someone to to buy the property from the scamer.)

Try to check with the barangay/municpaly office if that relative have paid tax at SAME property as toy have.

To avoid risk losing it you need to change it from only "rights" to TITLED in YOUR name. It's important the relative don't manage to title the property BEFORE you, but I guess he can't because the minimum demand is he has paid tax at it minimum 10 years.
If same family have had it since close after WWII, then it's much more SURE* to get the title approved, BUT  even if your family have had it that long time, DON'T do it in this case, because then they will check inheritance back BEFORE 1985 and then they will find the relative, who claim it now.

*In that "WWII" process they WILL say "Yes" after checking
ownership (who paid tax)
and heritage checking if no one else can have right to (part of) it (The other person will be shown in such check).

INSTEAD you can try to use an OTHER law which say you can APPLY to get it titled in your name. (In the "WWI" type they HAVE TO say Yes if they find both the demands fullfiled. In this type they can say "No" anyway, but they say Yes mostly. (A friend of mine got all the family properties approved ib her mother's name, except 2 who are classified as "Timberland". (I believe the rule is changed now, so it's some chance Timberland can be approved too.) She just applied and pay the fees. The fees are high compared to a common Filipino salary, but small compared to the value of the property, so it's surely worth it, if you can afford it.  (2011 was it common with 1000 - 2000p per title.) The minimum demand to have CHANCE to get it approved according to this rule is you have paid tax for it at least the last 10 years.


..
There are two ways "juridical" (through court which take long time and can cost very much
and "administrative". I believe this is the corect place and process for you:
Land Registration Authority (LRA) has significantly shortened its land titling process to five easy steps which can be taken in a single visit to any register of deeds (RD) office anywhere in the country.
It's much simplified compared to earlier.
Step 1. Submit the conveyance instrument and all supporting documents to the entry clerk at the RD. The applicant will receive an electronic primary entry book (EPEB) number to confirm receipt of the conveyance instrument and supporting documents.
Step 2. Pay the corresponding fees.
Step 3. The documents will be turned over to the examiner who will check if all the requirements have been met, after which the information would be encoded.
Step 4. If the requirements are complete, the RD approves the applicant.
Step 5. A new land title will finally be printed and issued to the applicant.

NOTE! NOTE! NOTE! Basicly this is very GOOD rule, BUT it has the CRAZY part saying the person who get the application approved FIRST, get the title!!!   So you better HURRY to try to get it BEFORE your relative.
Plus I would try to stop the other person's application to be approved, if the other person have started one. Try to get information from the officials if the other have made an application. I don't know if they answer such questions.

thank u for your inputs and advise. these are very much helpful. does that maen we have to check who paid the taxes prior to 1985?
land title is under the name of the (deceased)grandfather of my relative who's seeking right of that land.

No, you don't need to check before 1985 (except if you will go for the "WWII" alternative.)

Oh there IS a TITLE not only "rights" ?
If so, then you don't need to hurry to concerning the LAST part I wrote above.
But because the title isn't in your name, you better hurry to get it in your name, to reduce the risk.
I don't BELIEVE you risk to LOSE (whole) title,
BUT there are risks someone else can get for instance a Title "replacing lost" and use it to fool someone to buy it. Then you can get big trouble,

Who has the TCT?
Can you PROVE your line in the family have BOUGHT whole
OR got WHOLE and COMPENSATED the family line the other person belong to for their part of inheritance?
Otherwice it's risk the other person can get PART of the property LEGALY.

No one has a TCT as far as I'm aware. How to secure a TCT though?
We do not actually buy that property. That was an inherited property of my father's mom. Just so happened that their mom passed away in 1970s without having that property get titled under her name.
We have a copy of the Land Title under the name of Anselmo D. (father's mom inherited the property from him).

"We do not actually buy that property. That was an inherited property of my father's mom."
When it was inherited, the accets had to be SPLIT with the line of the relative, who claim it. Done by split the land, that line got same worth of assets, or that line was PAID OFF of your line to let their part of the property go.
If that line didn't get their share, then the claiming relative can have LEGAL claim to a PART of your property...
If you don't have documents telling what happened,. you can ask old people to try to get to know what's true.
What do the claiming relative say about WHY he find he has right to the property?
Check what the Register of Deeds say about who is owner. If it say different than what your copy say, you can demand a copy of that.

"We have a copy of the Land Title under the name of Anselmo D. (father's mom inherited the property from him). "
Oh. Then there is a risk the claiming relative can have the original.
You better hurry to try to get a title in YOUR name to reduce risk the claiming relative get whole.
Did the claiming relative's family line get their share too from that Anselmo?