Tenants unwilling to fill out W9 for security deposits

[Yuzi Stha]

I have recently acquired a new property with existing tenants living there. Previous owner was holding security deposits in non interest bearing accounts, as per law in Massachusetts we are required to put it in the interest bearing Massachusetts bank. I have contacted the bank to open those escrow accounts but bank said they would need W9 from tenants. I have the form to tenants but they are unwilling to fill those out, just want to hear back from other Massachusetts landlords on how they deal with these situations?

Thanks in advance..