Transaction agreement defining how specified mortgage assets are transferred, serviced, administered, and distributed to security holders.
A pooling and servicing agreement (PSA) is a transaction document that defines how specified mortgage assets are transferred, serviced, administered, and used to support distributions to security holders.
A pooling and servicing agreement matters because a private-label or other securitization can involve a depositor, seller, servicer, master servicer, trustee, custodian, administrator, and multiple investor classes. The agreement assigns rights and duties among those parties.
The PSA can address asset transfer, representations and warranties, document custody, servicing standards, collection accounts, remittances, advances, loss allocation, reporting, party replacement, and transaction termination. Not every MBS uses a document with this exact name, and no two agreements should be assumed identical.
The PSA is not the borrower’s note or security instrument. It governs transaction parties and does not erase applicable consumer law or silently amend the borrower’s contractual loan terms.
Borrowers rarely review a PSA during normal application or closing. The term is more likely to appear later if there is a servicing dispute, default issue, investor question, or explanation of how a securitized loan is administered.
The borrower-facing takeaway is that a servicer may follow investor and transaction requirements behind the account, while the borrower still interacts with the authorized servicer. References to investor limits should be evaluated alongside applicable law, agency rules, and the actual servicing authority rather than treated as a complete explanation by themselves.
| Subject | What the agreement may define |
|---|---|
| Pool formation | Which assets are transferred and accepted |
| Representations and remedies | Statements about loan characteristics and cures for qualifying breaches |
| Servicing | Collection, escrow, default, reporting, and loss-mitigation responsibilities |
| Cash administration | Accounts, remittances, fees, advances, and distribution priorities |
| Transaction parties | Trustee, servicer, master servicer, custodian, and administrator duties |
| Termination or replacement | Conditions for replacing a party or ending the transaction |
| Term | Main role |
|---|---|
| Mortgage Pool | Group of loans backing a transaction |
| Pooling and servicing agreement | Governing document for administration and servicing of the pool |
| Mortgage Servicer | Company handling borrower account administration |
| Master Servicer | Entity overseeing broader servicing administration for a pool |
| Mortgage Servicing Rights (MSR) | Rights to service the loan and receive servicing compensation |
A borrower’s loan is transferred into a private-label securitization. The borrower continues paying the named servicer, while the PSA requires that servicer to report collections to the master servicer and remit transaction funds according to a defined schedule.
The borrower requests payment assistance. The servicer evaluates the account under applicable law, the loan documents, delegated authority, and investor requirements. The borrower does not need to send the request directly to every security holder.
Pooling and servicing agreement differs from Mortgage Servicing Rights (MSR) because MSR describes the servicing asset or rights, while the PSA is a governing agreement for the pooled transaction.
It also differs from Servicing Transfer. A servicing transfer is a borrower-facing change in who collects payments; a PSA is a behind-the-scenes investor document.
It also differs from Master Servicer. The PSA is the governing document, while the master servicer is an entity operating under the servicing structure.
It differs from the PSA Prepayment Model. The shared acronym is coincidental: one is a legal agreement, while the other is a prepayment-speed convention.