Property to be sold but with 3 unit apartment

Good day Sir,

We are planning to sell a property with 3 rental apartment on it. The 3 tenant have been living there for 6 years. No lease contract were being signed.These tenants have no back dues.

1).What is the proper way of asking them to leave? because the buyer want the building unoccupied.

2). What if the tenant refuse to leave? what must be done? maybe because the rent is low.

Try to personally talk to the tenant and inform them that you are planning to sell the property, they might exercise their right of first refusal, meaning, they might offer you to buy the property based on a reasonable price, being the lessee, they have the right to buy the property ahead of other buyers, but if they don't want to buy the property, then you have the rigt to request them to leave the property. If they refuse to leave despite your verbal request, (a) sent them a letter demanding them to vacant the property, (you must have a proof that you sent them a written notice, example, a copy of the letter with their signature and date of receipt, or a registry return card); (b) file a complaint with the barangay, if it is still unsuccessful, request a certification to file action from the barangay, (c) file an ejectment case with the Metropolital / Municipal Trial Court.