A process server visits the same residence three weekdays in a row at approximately 2:00 PM. Nobody answers. The server records three attempts and asks whether substituted service is now available.

Another server visits the residence on a weekday evening, returns early on a different morning, and makes a weekend attempt after learning that the subject works irregular hours. Each report records access, vehicles, occupancy indicators, conversations, and what changed before the next visit.

Both files contain three attempts.

They do not necessarily show the same diligence.

Reasonable diligence is often reduced to a number because a number is easy to count. Field quality is harder to measure. It requires looking at whether the attempts were made in good faith, at meaningful times, at a location reasonably connected to the person, and with a strategy that responded to information learned along the way.

California is also changing the legal framework. Beginning January 1, 2027, AB 747 adds a specific statutory minimum for reasonable diligence under designated summons-service provisions. For covered service under Code of Civil Procedure section 415.20(b), the new language requires good-faith personal-delivery attempts on at least three occasions, on three different days, at three different times.

That rule matters. It still does not mean that every three-attempt history is equally strong, that every document requires three attempts, or that completing three visits automatically authorizes every alternative method.

1. What Reasonable Diligence Means Operationally

Reasonable diligence is a legal standard applied to particular service methods and facts. The responsible attorney or court determines the legal sufficiency of the record. The process server’s job is to perform and document a genuine effort that gives the reviewer reliable facts.

Operationally, a diligent attempt history should answer:

• What method was being attempted?
• Which person or legal recipient was being sought?
• Why was this location selected?
• On what dates and at what exact times did the attempts occur?
• Did the timing vary in a meaningful way?
• Did the server reach the actual door, office, or unit?
• What did the server do during each visit?
• What objective signs of occupancy or business activity were observed?
• Who was contacted, and what exactly did that person say?
• What was learned about the subject’s schedule or address?
• How did that information change the next attempt?
• Why did the process move to another permitted method or escalation?

Diligence is therefore both activity and record. An undocumented attempt may be difficult to evaluate. A detailed declaration cannot repair an attempt that never occurred or a strategy that ignored obvious information.

2. Start With the Legal Purpose

The phrase “due diligence” appears in process serving conversations as if it describes one universal checklist. It does not.

Diligence may be relevant when:

• personal delivery must be attempted before substituted service;
• a party requests permission for service by posting and mailing in an unlawful detainer matter;
• a party asks the court to authorize service by publication or posting because a person cannot be found;
• a court order requires specific attempts or investigation;
• a declaration must explain efforts to locate or contact a person;
• a law firm evaluates whether another service strategy is available.

Those purposes can require different work.

For substituted service of an individual summons under section 415.20(b), the focus is on good-faith efforts to personally deliver at appropriate locations and times before using the permitted substitute-delivery and mailing procedure.

For publication, the issue may include broader efforts to locate the person, such as reviewing known addresses, contacting appropriate sources, checking public records, or following other steps required by the court. Three door visits to one old address may be insufficient to show that the person cannot be found.

For unlawful detainer posting and mailing under section 415.45, the server and requesting party must follow the specific statute and obtain court authorization. Posting is not a method a field server selects independently because other attempts were unsuccessful.

Before counting attempts, review the assignment before service and identify the actual legal purpose.

3. The Practical Framework in 2026

As of October 2026, Code of Civil Procedure section 415.20(b) uses the phrase “reasonable diligence” for specified individual substituted service without the future AB 747 numerical definition yet being operative.

California Courts public instructions provide a practical framework for ordinary civil summons, family law, and eviction service. They generally tell the server to try personal delivery at least three times, on different days and at different times when the person is likely to be present.

That guidance is useful, but it should not be converted into the claim that California currently has one universal three-attempt rule for every document and recipient.

The correct 2026 analysis still depends on:

• the governing statute;
• the case type;
• the document being served;
• the person or entity receiving service;
• the proposed service method;
• the known residence and workplace information;
• any court order or local requirement;
• the quality of the actual attempts.

A server should follow current client instructions and governing authority, not apply the 2027 statute early as if it were already the operative rule.

4. What AB 747 Changes in 2027

AB 747, the Service of Process Accountability, Reform and Equity Act, changes specified California summons-service requirements beginning January 1, 2027.

For section 415.20(b), the new language states that reasonable diligence is shown by attempting personal delivery of the summons and complaint in good faith:

• on at least three occasions;
• on three different days;
• at three different times.

This makes the minimum structure more explicit for the covered service.

The statutory wording also makes good faith important. A company should not interpret the rule as permission to schedule three technically different times that have no realistic chance of reaching the subject.

For example, 1:55 PM, 2:05 PM, and 2:15 PM on three days are different times in a literal sense. If the company knows the subject works from 8:00 AM to 5:00 PM, the pattern may still raise an obvious quality question.

AB 747 also adds photographic requirements for covered completed and attempted summons service under sections 415.10, 415.20, and 415.45. The site photographs generally must contain a readable, automatically recorded date, time, and GPS or equivalent location stamp, with additional statutory requirements and exceptions.

The Judicial Council has developed revised forms and rules to implement the legislation. Providers should verify the adopted forms and operative instructions before January 1, 2027 rather than relying on an older POS-010 template.

5. What Makes an Attempt Good Faith

A good-faith attempt is a genuine effort to personally deliver the correct documents to the correct person.

It generally includes:

• traveling to the intended and reasonably verified location;
• reaching the relevant door, unit, suite, reception area, or lawful access point when possible;
• knocking, ringing, using the intercom, or following another appropriate contact procedure;
• waiting a reasonable amount of time for a response;
• asking for the named person without disclosing unnecessary case details;
• using available directory, reception, security, or management information appropriately;
• recording access limitations and objective observations;
• following up on credible information learned during the visit;
• creating the field record promptly and accurately.

A drive-by observation may be useful in a specific investigation, but it should not automatically be described as a complete personal-service attempt if the server never approached the location or tried to make contact.

A telephone call may help confirm hours or access, but it is not the same event as attempting personal delivery at the address.

A server should describe what actually happened. Do not upgrade “drove past, lights off” into “attempted personal service, no answer.”

6. Choose Times That Could Realistically Work

Varied timing is not an administrative detail. It is part of the strategy.

Someone who is unavailable at 11:00 AM on Tuesday may be home at 7:00 AM, 7:00 PM, or on Saturday. A business owner may arrive before the public opening time. A night-shift worker may be asleep during the afternoon but available in the morning.

Useful time windows may include:

• early morning before a normal commute;
• weekday evening after work;
• weekend morning or afternoon;
• business opening or closing periods;
• a time suggested by a credible occupant or employee;
• a lawful scheduled meeting or known public appearance;
• a window connected to documented vehicle activity.

Timing should remain lawful, safe, and professionally reasonable. The fact that a person may be home at 2:00 AM does not automatically make that an appropriate routine attempt.

Different Times Should Be Meaningfully Different

A useful variation tests a different availability theory.

The schedule should reflect the actual subject and location, not a generic route template.

7. Verify the Address Before Counting Visits

An attempt history can be perfectly timed and still be operationally weak if the address is wrong.

Before or during the first attempt, evaluate:

• whether the street address exists;
• whether the unit or suite number is complete;
• whether the subject is connected to the property;
• whether the address is residential, commercial, virtual, vacant, or a mail facility;
• whether the business name matches the assignment;
• whether directories or mailboxes show the subject;
• whether credible occupants or management report that the person moved;
• whether the client supplied an outdated or conflicting address.

Suppose the first visit reveals that Unit 12 does not exist. Two more attempts to Unit 12 do not improve the case. The assignment needs clarification.

Suppose a current leasing agent says the subject moved out eight months ago and gives a documented move-out date. Repeating visits may waste the deadline. The team should evaluate another address or locate research.

Suppose an unidentified neighbor says, “I do not think she lives here,” while a matching vehicle, directory name, and current package are visible. The address should not be rejected from that statement alone. The source and surrounding facts matter.

8. Attempt Count Is Not Attempt Quality

The easiest metric in process serving is the number of attempts. It is also one of the easiest metrics to misuse.

A count does not show:

• whether the server reached the correct door;
• whether the time was likely to reach the subject;
• whether the address remained credible;
• whether the server used the intercom or reception desk;
• whether anyone provided schedule information;
• whether access prevented contact;
• whether the next attempt changed after new information;
• whether the report accurately describes the event.

A high-quality attempt narrows the next decision. It confirms a location, identifies an access problem, reveals a schedule, supports another time window, or shows that the address should be reconsidered.

A low-quality attempt changes only the counter.

This is why repeating the same attempt usually does not fix the underlying problem.

9. Let Each Attempt Inform the Next One

Diligence should be cumulative. The case should know more after each visit.

If the Address Appears Active

Interior lights, a matching vehicle, recent packages, maintained landscaping, a directory name, or credible occupant information may support another attempt at a different time.

If the Subject Has a Known Schedule

A household member says the subject leaves for work at 6:30 AM. The next attempt should consider the information rather than repeat an afternoon visit.

If the Workplace Confirms Employment

Reception says the subject works remotely on Mondays and is normally in the office on Wednesday. A Wednesday attempt may be more meaningful than another random visit.

If the Property Appears Vacant

Removed utilities, construction, accumulated notices, no furnishings, or a property manager’s statement may justify address review before another fee is incurred.

If Access Is the Main Problem

The next action may require a gate code, leasing-office schedule, staffed security window, unit directory check, or another lawful access strategy.

The field server records facts. The operations team connects those facts to the deadline, instructions, known addresses, and permitted methods.

10. Document Access Barriers Correctly

A locked gate, secured lobby, unmanned reception desk, controlled elevator, or security checkpoint can prevent the server from reaching the intended door.

That does not make the visit meaningless. It changes what the visit establishes.

A useful access-limited report should state:

• the exact address and entrance used;
• whether the gate or lobby door was locked;
• whether an intercom, callbox, directory, or telephone number was available;
• whether the subject or unit was listed;
• which buttons or contacts the server tried;
• whether security, reception, or management was staffed;
• what the server asked and what response was received;
• whether access was refused, unavailable, or never answered;
• whether the intended door was reached;
• what may improve access on the next visit.

Weak:

No answer.

Useful:

Arrived at the listed apartment complex at 6:22 PM. The exterior pedestrian gate was locked. The directory listed “R. Patel” at Unit 308. I called Unit 308 twice through the callbox and waited approximately four minutes after each call. No response. The leasing office was closed, and no security staff were present. I did not reach the unit door.

The useful note prevents a later reviewer from assuming that the server knocked at Unit 308.

11. Use Residence and Workplace Attempts Strategically

A residential attempt and a workplace attempt test different information.

A residence may provide access to early-morning, evening, and weekend availability. A workplace may confirm employment, department, schedule, travel, or remote-work patterns.

Before attempting a workplace, confirm:

• that the subject is currently connected to the employer;
• the physical office rather than a virtual or mailing address;
• public operating hours;
• the building’s security and reception procedures;
• the client’s instructions and any safety concerns;
• whether another method is authorized if personal contact fails.

Do not unnecessarily disclose the lawsuit to coworkers. Ask for the subject by name and record the role of anyone who provides information.

A mixed location history may demonstrate a broader effort than repeated visits to one location. That does not mean every case requires workplace service. It means the strategy should use reliable information that is actually available.

12. Special 2027 Consumer-Debt Requirement

Under the section 415.20(b) language operative January 1, 2027, an action to collect consumer debt carries an additional residence-related condition.

At least one of the required good-faith personal-delivery attempts must be made at the person’s dwelling place or usual place of abode when that location is known or can be determined with reasonable effort.

This means a provider should identify the case type during intake. A system that sees only “civil summons” may miss a requirement that depends on the nature of the action.

The case record should show:

• whether the matter is an action to collect consumer debt;
• whether a dwelling or usual abode is known;
• what reasonable effort was used to identify one if necessary;
• which attempt satisfied the residence component;
• the date, time, location, and result of that attempt.

A workplace-only attempt history may therefore create a specific problem in a covered consumer-debt action when a residence was known or reasonably determinable.

13. Not Every Document Uses the Same Diligence Standard

The three-attempt discussion most often concerns a summons and proposed substituted service. It should not be copied into every assignment.

Different matters may involve:

• personal service required without a substituted option;
• service by mail or electronic service when lawfully authorized;
• special rules for small claims;
• family law forms and procedures;
• restraining orders requiring personal delivery to the restrained person;
• subpoenas with document-specific requirements;
• unlawful detainer procedures and court-authorized posting;
• service on corporations, public entities, minors, conservatees, or other recipients;
• court orders prescribing a particular method or attempt schedule.

The distinction between personal and substituted service should be resolved from the documents and applicable authority, not from the number of unsuccessful visits alone.

A server should never tell a household member, “I can serve you because this is my third try,” without knowing that the method, recipient, location, and mailing requirements are legally available.

14. Prepare a Useful Declaration of Due Diligence

California Courts explains that a Declaration of Due Diligence should describe every time the server tried personal service, including the dates, times, locations, and results. In the ordinary civil substituted-service workflow, it is attached to the Proof of Service of Summons.

The declaration should be built from contemporaneous process server field notes, not reconstructed weeks later.

Include the Foundation

Identify the server, the person sought, the documents, and the address or addresses attempted. Use the correct case caption and case number.

List Every Relevant Attempt Chronologically

For each attempt, state:

• the full date;
• the exact local time;
• the complete address, unit, or suite;
• the type of location;
• what the server did;
• whether the actual door was reached;
• objective observations;
• contacts and exact relevant statements;
• the result.

Explain Address or Access Issues

If the server could not reach the unit, say so. If the suite did not exist, say so. If the subject was not listed, say so. Avoid compressing different events into “no answer.”

Separate Fact From Interpretation

Use “The manager stated that the subject moved out in May 2026,” not “bad address,” unless the conclusion is supported and appropriately stated.

Use “I heard movement after knocking, but nobody answered,” not “subject was hiding.”

Do Not Omit Failed or Inconvenient Attempts

A declaration should not be curated to make the history look better. If a visit occurred after business hours or at the wrong unit, the internal record should preserve that fact. The operations team and attorney can determine what belongs in the filed declaration and how to address an error.

Sign Only What the Server Knows to Be True

A declaration is made under penalty of perjury. The server should review the final version and confirm that it matches the original notes before signing.

15. Weak and Strong Attempt Histories

Weak Residential History

• Monday, 1:40 PM: No answer.
• Tuesday, 1:55 PM: No answer.
• Wednesday, 2:05 PM: No answer.

The history shows three dates and slightly different times. It does not show whether the correct unit was reached, whether the address appeared active, whether the server used an intercom, whether anyone provided information, or why the same daytime window was repeated.

Stronger Residential History

• Tuesday, 7:08 AM: Reached the listed single-family residence. Knocked twice and rang the doorbell. No response. A silver Toyota matching the client-provided vehicle description was parked in the driveway.
• Thursday, 6:52 PM: Lights were visible in the front room. After knocking, an adult female answered and stated that the subject lives at the address but works late on Thursdays. She declined to provide her name. No documents were left.
• Saturday, 10:16 AM: Returned based on the occupancy information. Reached the front door and knocked twice. No response. The matching Toyota was not present. A package at the door displayed the subject’s last name.

This history does not guarantee that every legal requirement is satisfied. It gives the reviewer a much clearer record of good-faith effort, address connection, varied timing, and information learned.

Weak Workplace History

• Three attempts at 6:30 PM after the office closed.

Stronger Workplace History

• First attempt during published business hours. Reception confirmed current employment but said the subject was off-site.
• Second attempt at the time reception said the subject usually arrived. Security reported the subject was working remotely.
• Third attempt on the next reported in-office day. Reception called the department, but the subject had left for a client meeting.

The stronger record shows why each attempt occurred when it did.

Wrong-Address History

• First visit: New occupant states subject moved before the occupant’s lease began.
• Property manager confirms subject is not a current tenant and provides a documented move-out month.

The next best action may be address research, not a third identical visit.

16. Know When to Change the Strategy

A diligent operation does not keep the field server moving without evaluating whether the assignment is progressing.

Escalate when:

• the address is materially questioned;
• the unit or suite cannot be confirmed;
• access prevents every attempt from reaching the location;
• credible information shows the subject works or resides elsewhere;
• the remaining deadline no longer supports routine timing;
• the subject appears to keep an irregular schedule;
• attempts reveal a possible avoidance pattern;
• the proposed substitute recipient or location is uncertain;
• the documents may require personal service only;
• court authorization may be needed for another method;
• the case type creates an additional statutory requirement;
• safety conditions change the field plan.

Possible next actions include:

• another attempt during a genuinely different time window;
• a workplace or alternate residential attempt;
• unit, suite, or gate-code clarification;
• address verification or skip tracing;
• coordination for a difficult-service strategy;
• a lawful stakeout request when appropriate;
• client or attorney review of another service method;
• a request for court authorization where required.

Escalation is not an admission of failure. It is evidence that someone is managing the assignment instead of waiting for the deadline to make the decision.

17. Reasonable Diligence Checklist

Before the First Attempt

• Identify the documents and case type.
• Confirm the person or entity being served.
• Identify the purpose of the diligence record.
• Confirm the authorized service methods.
• Verify the address, unit, suite, and location type.
• Review photographs, vehicles, schedules, and prior notes.
• Record the deadline and hearing date.
• For 2027 assignments, identify whether the applicable AB 747 requirements apply.
• Identify consumer-debt matters when relevant.

For Each Attempt

• Record the exact date and time.
• Record the complete location.
• State whether the actual door, unit, or office was reached.
• Describe the actions taken.
• Record access conditions.
• Record objective occupancy or business observations.
• Attribute third-party statements accurately.
• State the result without speculation.
• Capture required photographic and location evidence.
• Recommend or trigger the next action.

Before Another Attempt

• Review what the previous visit established.
• Choose a time that tests a different realistic availability window.
• Confirm that the address remains credible.
• Resolve avoidable access problems.
• Check the remaining deadline.
• Escalate if the same obstacle is repeating.

Before Substituted or Alternative Service

• Confirm that the method is legally available for the documents.
• Confirm that the required diligence standard has been met.
• Confirm the substitute recipient and location requirements.
• Confirm any required mailing step.
• Obtain court authorization when required.
• Prepare the declaration from verified attempt records.
• Review the declaration and proof for consistency.

18. How Managed Operations Improve Diligence

Reasonable diligence is often discussed as a field-server responsibility. The quality of the record also depends on assignment management.

The server cannot choose good timing if the deadline is hidden. The server cannot evaluate a residence requirement if the case type is missing. The server cannot adapt to a prior conversation if the earlier note is stored in someone else’s text messages. The server cannot verify the address if a corrected unit number never reaches the field assignment.

A managed operation keeps the following connected:

• documents and case type;
• recipient information;
• all known addresses;
• deadline and hearing date;
• attempt schedule;
• field notes and observations;
• photos and GPS data;
• client communications;
• address concerns;
• next actions and escalations;
• mailing events;
• Declaration of Due Diligence;
• Proof of Service.

This allows the operations team to see whether the assignment is accumulating useful facts or merely accumulating visits.

It also makes 2027 preparation practical. The company can verify different days and times, identify the required residence attempt in a consumer-debt matter, connect stamped site photographs to the correct attempt, and build the declaration from structured data.

Reasonable diligence should not be treated as a phrase added to a proof after the work is done. It should be visible in how the assignment was planned, performed, reviewed, and documented.

Three attempts may satisfy a numerical minimum in a covered case. The professional question remains whether those attempts show a genuine effort to reach the correct person.

This article is for general educational and operational information and is not legal advice. Reasonable diligence and service requirements depend on the documents, case type, recipient, service method, service date, statute, court order, local procedure, and facts. The responsible attorney and court determine legal sufficiency.