Below is a comprehensive discussion of the modes of service of pleadings under Rule 13 of the Rules of Court (Philippines), incorporating the significant changes introduced by the 2019 Amendments to the 1997 Rules of Civil Procedure (which took effect on May 1, 2020). This includes a detailed look at each mode of service, the preference or hierarchy among modes, relevant procedural requirements, and key points of jurisprudence.

I. Overview: Filing vs. Service

Filing – This refers to the act of presenting pleadings and other papers to the court. A document is deemed “filed” on the date and time it is actually received by the court (personally or electronically), or on the date of mailing or deposit with an accredited courier (if the proper conditions under the rules are met).
Service – This refers to the act of delivering or furnishing a copy of the pleading, motion, notice, order, judgment, or other paper to the parties or their counsel of record. Ensuring proper service is crucial for due process—every litigant must have notice and an opportunity to be heard.

Under Rule 13, pleadings, motions, notices, orders, judgments, and all other court submissions must be served upon the parties affected. Counsel typically receives such service on behalf of the party represented.

II. General Rules and Preference in Modes of Service

Primacy of Personal Service
As a rule, the Rules of Court (both the 1997 and 2019 amendments) prefer personal service over other modes whenever practicable.
Reasons for Substitution
Other modes of service may be resorted to only if personal service is not practicable, and subject to the hierarchy or preferences laid out in Rule 13.
Proof and Completeness of Service
The date and manner of service impact how periods (e.g., time to file responsive pleadings, motions, appeals) are computed. Proof of service (such as an affidavit of service, registry receipt, or courier official receipt) is mandatory. Failure to show proper service may result in the court disregarding the pleading or paper.

III. Modes of Service of Pleadings Under Rule 13

1. Personal Service

(Rule 13, Section 6)

Definition
Personal service is effected by delivering a copy of the paper personally to the party or counsel, or by leaving it in their office (or residence if office delivery is not possible) with a competent person in charge thereof.
Manner of Accomplishment
- Hand the copy directly to the party or counsel of record.
- If the party or counsel is not found at the office, the copy may be left with a responsible person who could acknowledge receipt.
- If at the residence, the copy may be left with a family member of sufficient age and discretion who could acknowledge receipt.
Completeness and Proof
- Service is complete upon actual delivery.
- Proof of personal service may be shown by:
  - Written admission from the person served, or
  - Official return from the server or affidavit of the server, containing the date, place, and manner of service.
Preference
- The rules emphasize that personal service must be attempted first or used whenever practicable, as it is the surest way to notify the party or counsel.

2. Service by Mail

(Rule 13, Sections 7 and 8)

Under the previous version of Rule 13, “service by mail” was done through the Philippine Postal Service (PPS) either by ordinary mail or by registered mail. The 2019 Amendments now commonly refer to “service by mail” primarily through registered mail, although a fallback to ordinary mail still exists under certain conditions.

Registered Mail
- Definition: Mailing a copy of the pleading via registered mail with the Philippine Postal Corporation (or accredited private courier, as allowed) ensuring a “registry receipt” is obtained.
- Completeness: Service by registered mail is deemed complete upon actual receipt by the addressee, or after five (5) days from the date he or she received the first notice of the postmaster, whichever date is earlier.
- Proof:
  - Registry receipt from the post office (or the courier’s official receipt), and
  - Affidavit of mailing by the person who caused the mailing, demonstrating compliance with the rules (date, place of mailing, etc.).
Ordinary Mail
- When Allowed: Only if no registry service is available in the locality of either the sender or addressee, or in other exceptional circumstances specified by the rules or jurisprudence.
- Completeness: Deemed complete upon the expiration of ten (10) days after mailing, unless evidence shows otherwise.
- Proof: Affidavit of mailing, along with an explanation of why service by registered mail was impracticable.

3. Accredited Courier

(Rule 13, Section 7(b))

The 2019 Amendments explicitly recognize accredited courier (private courier services that the Supreme Court or the Office of the Court Administrator may approve).

Definition
- Filing or service is done by depositing the pleading or document in a sealed envelope, addressed to the party or counsel, with an accredited courier who issues an official receipt or document tracking number.
Completeness
- Service by accredited courier is deemed complete upon actual receipt by the addressee, or after at least two (2) attempts to deliver by the courier, or upon expiration of five (5) calendar days from the first attempt to deliver, whichever is earlier.
Proof
- Courier official receipt (or tracking slip) plus
- Affidavit of service by the person who deposited the document with the courier, stating the date, place of deposit, and tracking or reference number, as well as a statement on the status of the attempts to deliver.

4. Electronic Means (E-Service and E-Filing)

(Rule 13, Sections 9, 10, and related provisions; A.M. No. 19-10-20-SC)

The 2019 Amendments ushered in the official recognition and regulation of electronic service (e-service) and electronic filing (e-filing). Courts are increasingly encouraging the use of electronic means to speed up proceedings, subject to specific guidelines.

Electronic Service
- Allowed Methods: E-mail, facsimile transmission (fax), or other electronic means as the Supreme Court may approve in the future.
- Consent or Order: E-service may be done if (a) the party to be served consents to e-service, or (b) the court orders e-service, or (c) the rules specifically allow e-service for that type of paper.
- Completeness:
  - If service is by e-mail, it is complete at the time of the electronic transmission, unless the serving party learns that it did not reach the addressee.
  - If service is by fax, it is complete upon receipt of the fax confirmation.
- Proof:
  - For e-mail, proof of service can be in the form of a printed copy of the sent e-mail with attachments, plus an affidavit attesting to the fact of such service.
  - For fax, proof is the transmission verification report plus an affidavit of service.
Electronic Filing
- Parties who are authorized or required by court issuance to e-file must observe the guidelines on the platform, format, digital signatures, etc.
- The date of e-filing is the date and time (Philippine Standard Time) indicated in the court’s Electronic Filing Service Provider system, subject to payment of the necessary fees within the prescribed period.
Applicability
- E-service and e-filing remain subject to the specific guidelines issued by the Supreme Court, including pilot programs in certain jurisdictions or for certain case types.

5. Substituted Service (of Papers, Not Summons)

(Rule 13, Section 8(b), old rules; integrated into new rules)

Distinction from Summons: Substituted service of pleadings under Rule 13 is different from substituted service of summons under Rule 14.
When Availed of: Substituted service of pleadings and other papers may be used if the party or counsel cannot be served personally despite diligent efforts, and service by mail/courier is not feasible.
Manner: Leaving the copy at the party’s or counsel’s residence with a person of sufficient age and discretion, or at the counsel’s office with a responsible person who can receive it.
Proof: An affidavit of service indicating that personal service and service by other means were not practicable, and specifying the details of the substituted service.

IV. Hierarchy of Modes; Explanation of Non-Personal Service

Despite multiple permissible modes, the Rules of Court and jurisprudence instruct that:

Personal service is preferred.
If personal service is not practicable, service by registered mail or accredited courier may be resorted to.
If registered mail or courier is not feasible, or if the court so orders, electronic means may be used.
Substituted service of pleadings or papers is generally a last resort when personal or mail/courier service is truly not feasible.

A party (or counsel) must always explain in the proof of service (usually in the affidavit of service) why personal service was not practicable when opting for other modes of service.

V. Completeness of Service and Counting of Periods

Personal Service – Complete upon actual receipt.
Registered Mail – Complete upon actual receipt or five (5) days from receipt of the first notice, whichever is earlier.
Ordinary Mail – Complete ten (10) days from mailing (rarely used unless no registry is available).
Accredited Courier – Complete upon actual receipt, or after at least two (2) attempts to deliver, or after five (5) days from first attempt to deliver, whichever is earlier.
Electronic Service – Complete upon successful electronic transmission (if by e-mail, at the time it leaves the server of the sender unless the sender receives notice of a failed transmission).

These points of completion are critical in computing time periods for filing responsive pleadings (e.g., answer, motion for reconsideration, motion for new trial), appeals, and other procedural steps.

VI. Proof of Service

Rule 13 also mandates that every pleading or paper filed (excluding the initiatory pleading at the commencement of an action, which is governed by Rule 14 regarding summons) must contain a proof of service to the other parties, typically found in the caption or at the bottom portion of the pleading as a “Notice of Service and Explanation,” or by a separate affidavit of service.

Mandatory Proof of Service
- Without proof of service, the court may refuse to consider the pleading or paper.
- If not attached, the court may require the filing of the proof and hold the paper in abeyance.
Acceptable Forms of Proof
- Registry receipt and affidavit of mailing (for service via registered mail).
- Official receipt and tracking reference (for accredited courier).
- Affidavit of service indicating date, place, manner of service, identity of person served.
- Printed e-mail with attachments, plus an affidavit attesting to e-service details, or fax confirmation (for electronic means).
Substantial Compliance
- Courts can accept substantial compliance if the proof of service clearly shows the manner, date, and recipient of the service, provided the served party does not contest it or claim prejudice.

VII. Common Pitfalls and Notable Jurisprudence

Failure to Attach Proof – Pleadings or motions lacking proof of service may be expunged or stricken from the record.
Incorrect Address or E-mail – Service is invalid if sent to a wrong or outdated address/e-mail, unless actual receipt is shown and no party is prejudiced.
No Explanation Why Personal Service Is Not Practicable – When parties jump straight to service by mail, courier, or e-mail without explaining why personal service was impracticable, courts may consider such service defective.
Presumption of Completeness – Once a party proves compliance with the rules (e.g., registry return receipt, affidavit of mailing), there is a presumption that service was completed. The burden shifts to the addressee to rebut that presumption with clear evidence (e.g., no actual receipt, or defective address).

Illustrative cases often stress that litigants and counsel must adhere strictly to the rules on service. The Supreme Court repeatedly reminds counsels: “Procedural rules are not to be belittled or dismissed, for they are tools designed to facilitate the adjudication of cases.” (See e.g., Solar Team Entertainment, Inc. v. How, 358 Phil. 324 (1998)).

VIII. Practical Tips and Best Practices

Always Attempt Personal Service First – It is the safest and most straightforward method.
Document Everything – Keep a copy of registry receipts, courier receipts, fax confirmations, e-mail transmissions, and attach them to the proof of service or affidavit of service.
Verify Addresses – Ensure that the address of the party or counsel of record is up-to-date, especially if the counsel files a notice of change of address.
Observe Time Stamps – Whether filing electronically or via courier, pay attention to time stamps and official receipts to avoid missing any deadlines.
Explain Why Personal Service Not Practicable – If you resort to mail, courier, or e-service, always comply with the rule requiring an explanation, if the rules so require (particularly in older jurisprudence).
Check Local Court Issuances – Some courts have pilot programs or specific guidelines on e-filing and e-service. Strictly comply with these local issuances to avoid technical lapses.

IX. Conclusion

The rules on modes of service of pleadings (Rule 13) are designed to ensure prompt, certain, and efficient notification of all parties, safeguarding their right to due process. Under the 2019 Amendments, the Rules of Court have embraced electronic means alongside the traditional modes (personal service, mail, courier). Despite such modernization, personal service remains preferred whenever feasible.

All counsel and parties are expected to observe these rules meticulously, attach proper proofs of service, and remain vigilant about addresses and deadlines. Failure to do so can result in pleadings being disregarded, adverse rulings, or even malpractice issues for lawyers who fail to protect their client’s interests.

By thoroughly understanding and following Rule 13, litigants uphold procedural due process and the speedy disposition of cases, which is the ultimate aim of all procedural rules.