Published October 16, 2026. An IRS- and GSA-grounded workflow for travel expense intake, substantiation, per diem references, reimbursement review, and exception routing.
Decision this research supports
A business may want an executive assistant to assemble travel expenses, but “do the expenses” hides several decisions. The organization must decide which policy applies, who incurred the cost, whether the trip had a documented business purpose, which amounts were advanced or paid directly, which evidence is required, and who approves reimbursement. The assistant’s role is best framed as preparing a complete, reviewable packet. The tax owner or employer retains decisions about deductibility, accountable-plan treatment, exceptions, and reporting.
What Publication 463 establishes
IRS Publication 463 explains travel, gift, and car expense rules, the records used to substantiate expenses, and treatment of reimbursements. It emphasizes timely written records and supporting evidence. It also distinguishes facts such as amount, date, place, and business purpose. This supports a structured intake rather than a folder of receipts. A receipt alone may show a charge but not why it was business-related, while a calendar entry may show a meeting but not the amount or payment method.
Build the packet around evidence elements
For each item, record traveler, trip identifier, transaction date, merchant, location, category, amount, currency, payment method, business purpose, attendees when policy requires them, and the linked receipt or statement. Preserve the original file and record any conversion rate separately. Link employer-paid bookings and advances even when they are not reimbursement requests, because the reviewer needs the full trip picture. Missing evidence should create a visible exception, not an invented description or a silently substituted amount.
Use per diem references carefully
GSA publishes federal per diem rates for official travel, including lodging and meals-and-incidental-expense components. A private organization may reference those rates only under its own approved policy and applicable tax advice. The assistant should record the location, travel dates, rate source, retrieval date, and any first- or last-day treatment specified by policy. Do not assume a per diem automatically applies, proves business purpose, or removes every documentation requirement. Save the rate evidence used so a later reviewer can reproduce the calculation.
Separate preparation from approval
The preparer can reconcile receipts, flag duplicates, identify unspent advances, and calculate totals under a written method. The approver should confirm business purpose, policy exceptions, and final reimbursement. If the traveler is also the approver, route to the alternate owner. Preserve both the submitted and approved versions and record adjustments with a reason. Editing the original claim to match the approved amount erases evidence and makes later reconstruction harder.
Manage deadlines and exceptions
The workflow should define submission windows, approval cutoffs, return-of-excess procedures, missing-receipt declarations, currency questions, mixed personal and business charges, cancellations, refunds, loyalty credits, and disputed card charges. The assistant can calculate dates from the approved policy and send reminders, but should not waive a deadline or create a receipt. An exception log should show the case, missing element, person contacted, due date, decision owner, resolution, and effect on payment.
Quality checks before handoff
Check that every claimed line has a unique identifier, required evidence, consistent currency, a stated purpose, and a reconciliation status. Compare card totals, reimbursement totals, advances, refunds, and direct-paid items without double counting. Confirm that files open and that restricted data is stored only in the approved location. The final packet should include a cover summary, unresolved exceptions, calculation notes, approval record, and retention location. Sampling completed packets helps reveal recurring policy or training gaps.
Method
We reviewed the named primary government sources on October 16, 2026, extracted statements relevant to the workflow, and separated those statements from our operational analysis. We compared the source requirements or guidance with the records an assistant can realistically prepare, route, and preserve. This is desk research, not an experiment, legal opinion, audit, or vendor comparison. A recommendation below is an inference about safer process design; it is not a claim that a checklist guarantees compliance, accuracy, security, or a business outcome.
What an assistant can and cannot own
An assistant can maintain the intake queue, check required fields, attach source records, identify missing information, calculate a due date from an approved rule, route an exception, and preserve the decision trail. The accountable owner must set policy, interpret disputed requirements, approve exceptions, and decide any legal, tax, employment, accounting, security, or customer remedy. Write that boundary into the procedure. A well-run handoff makes retained judgment visible instead of quietly shifting it to the person doing the administrative work.
Implementation pattern
Pilot one representative workflow for two weeks. Give it a named owner, a versioned instruction, a controlled source of truth, required fields, permitted actions, stop conditions, and an escalation route. Collect both ordinary cases and exceptions. At review, examine missing-input rate, queue age, correction rate, approval delay, and whether another authorized person can reconstruct each outcome. Change one control at a time where practical, record why it changed, and set the next review date before expanding scope.
Evidence packet design
A useful evidence packet begins with a stable case identifier and a short cover record: request received, applicable workflow version, current owner, status, due date, and unresolved questions. Attach source records without rewriting them, and create a separate activity log for checks, calculations, communications, approvals, and corrections. Each derived value should point to its inputs and method. Each exception should show what is missing, why it matters, who can decide, and when the case will be revisited. Preserve the submitted version as well as the approved outcome. Restrict sensitive fields to the smallest audience that needs them, and use links to controlled records instead of scattering copies across chat, email, and personal storage. A backup reviewer should be able to locate the governing instruction, reproduce material calculations, distinguish facts from interpretation, and see exactly where accountable judgment entered the process. If that reconstruction depends on memory, the packet is not ready.
Quality assurance and change control
Quality review should combine field validation with consequence-based sampling. Automated checks can detect missing identifiers, invalid dates, duplicate amounts, broken links, and status contradictions; they cannot decide whether a purpose is legitimate, an exception is reasonable, or a conclusion is sound. Define which outputs require pre-release approval and which may be sampled later. Track corrections by category and denominator so a changing workload does not distort the trend. When a rule, source, or system changes, record the change owner, effective date, affected cases, migration decision, and communication. Retest the workflow with an ordinary case, an exception, an unavailable approver, and a correction. The goal is not a perfect-looking dashboard. It is early detection, a recoverable record, and a clear route from evidence to an authorized decision.
Limitations
The cited materials have different purposes and coverage. Federal tax, employment, statistical, consumer-protection, security, and internal-control sources do not automatically apply to every organization, worker, transaction, or jurisdiction. Source pages and underlying rules can change after the checked date. Local law, contracts, industry rules, system design, and the facts of a case may require a different process. Readers should validate applicability with qualified owners and use this framework to organize evidence, not to replace professional judgment.
Buyer conclusion
The staffing decision is strongest when the buyer can name the output, source, authority boundary, acceptance check, and exception owner before delegating. That design lets an assistant contribute useful coordination without being asked to invent policy or make an unreviewed high-consequence decision. Buyers comparing providers should ask to see how work is queued, evidenced, reviewed, corrected, and handed back. The useful proof is a traceable sample and a functioning escalation path, not a broad promise that an assistant can handle everything.
Sources
- Publication 463 (2025), Travel, Gift, and Car Expenses - Internal Revenue Service. Checked October 16, 2026.
- About Publication 463 - Internal Revenue Service. Checked October 16, 2026.
- Per Diem Rates - U.S. General Services Administration. Checked October 16, 2026.
