Status: checked against official sources; automated independent review
FREQUENT FLYER GLOSSARY
What is a retroactive credit window?
Retroactive credit window (also retro-claim period or missing-credit deadline) is the time limit within which a loyalty programme member must ask for a flight, hotel stay or partner transaction to be credited after it fails to post to the account automatically. The clock normally starts on the date of the activity rather than the date the member notices the gap, and published limits differ: Delta Air Lines SkyMiles requires written account discrepancies within nine months [5], while United Airlines MileagePlus requires claims and supporting proof within twelve months [8].
Facts checked: 18 October 2026
Key takeaways
- The window is counted from the activity date, not from the moment a member spots the missing credit: nine months at Delta SkyMiles [5], twelve months at United MileagePlus [8] and one year at Marriott Bonvoy [4].
- It is a deadline attached to a claim, not the claim itself: a member still has to submit the request through the programme's own channel, with the evidence that programme asks for [4] [5] [8].
- Normal posting comes first. Delta says mileage is credited within up to eight weeks of qualifying activity unless a partner's terms say otherwise, and Marriott Bonvoy allows up to ten days for transactions at a Participating Outlet [5] [4].
How a retroactive credit window works
Loyalty programmes treat automatic posting as the normal route, so the retroactive window only becomes relevant once a transaction has failed to appear. A member waits out the expected posting period, checks the account, and then converts the gap into a claim. The window fixes how long that claim stays open, which is why it matters to anyone who flies on a partner airline, books a hotel under a rate that may not be eligible, or gives a membership number at a partner counter.
The window and the claim are two different things. The claim is the action: the online form, letter or call, plus whatever documents the programme wants. The window is the deadline attached to that action, and it is measured from the activity, so a member who notices a missing flight months later has less of the allowance left. Delta frames it as an account discrepancy that must be reported in writing within nine months of the activity date, and it does not accept verbal notification [5]. United requires a member's claim and proof of that claim to reach it within twelve months after the date the mileage or Premier Qualifying Credit was claimed to be earned [8]. Marriott Bonvoy requires missing-credit requests to be received within one year of the applicable activity, unless its programme rules or supplemental terms state otherwise [4].
Because each programme writes its own limit, a deadline learned in one scheme does not carry across to another, and a partner transaction can sit under the partner's timing as well as the airline's. For the practical sequence of gathering documents and filing, see the missing miles claim walkthrough.
What deadlines do Delta, United and Marriott Bonvoy set?
| Programme | Where the clock starts | Deadline |
|---|---|---|
| Delta Air Lines SkyMiles | Date of the activity | Nine months, reported in writing [5] |
| United Airlines MileagePlus | Date the mileage or credit was claimed to be earned | Twelve months, covering the claim and its proof [8] |
| Marriott Bonvoy | Date of the applicable activity | One year, unless its rules or supplemental terms state otherwise [4] |
Delta separates two moments inside its nine-month limit. It asks members to act once credit has not been recorded within 90 days for a qualifying partner activity, or 30 days for a Delta or Delta Connection flight, and to send airline-partner documentation to SkyMiles Account Support; for car, hotel and miscellaneous partner activity the member contacts the partner directly [5]. The nine-month written-discrepancy deadline is the outer limit that applies to the account [5].
United states the twelve-month limit as a condition on claims and on the proof that supports them, and adds that certain partners may operate valid retro-credit claim periods that differ [8]. Marriott Bonvoy's one-year limit is expressly subject to any posting timelines, request channels, documentation requirements and property- or programme-specific procedures set out elsewhere in its rules [4]. For hotel-specific steps, see the hotel missing stay credit checklist.
What proof does a retroactive credit claim need?
A retroactive request is decided on evidence, and the window applies to the evidence as much as to the request. United reserves the right to require proof, including copies of tickets, receipts or similar documentation verifying the transactions claimed [8]. Delta asks members to keep copies of tickets or ticket receipts and boarding passes until the credit appears, and says altered or illegible documents will not be accepted [5]. Marriott Bonvoy routes missing-credit requests through its own channels or Member Support, subject to documentation requirements and property- or programme-specific procedures [4].
Two practical consequences follow from the rules. First, documents need to be kept for months, because Delta's expected posting period runs to eight weeks before a claim is even due [5]. Second, partner flights add a layer: eligibility depends on the partner's own offer terms, which Delta lists as a condition of credit [5]. The partner flight credit checklist covers that step.
What are the exceptions and limits?
- Activity before enrolment. Delta will credit travel flown up to 30 days before enrolment if the member asks at the time of enrolment [5]. Marriott Bonvoy lets new members request credit for eligible activity completed in the 30 days before enrolment, provided the request is made within one year; qualifying activity from before that period, and Participating Outlet charges without a stay, are not eligible [4].
- Partner timing. United warns that some partners set their own valid retro-credit claim periods, so the airline's twelve-month limit is not automatically the partner's limit [8].
- One programme per activity. Delta says Delta, airline partner, hotel and car rental activity can be credited in only one mileage programme and cannot be transferred once recorded [5].
- Late or informal requests. Delta does not accept verbal notification and requires the discrepancy in writing within nine months [5]; United requires the claim and its proof to be received within twelve months [8].
- Outside this term. A retroactive credit window covers activity that never posted. Correcting a posting error, reversing a points transfer, and appealing a status-credit decision are separate matters with their own processes.
Frequently asked questions
Does the retroactive credit window start when I notice the missing credit?
No. Programme deadlines are measured from the activity: Delta uses the date of the activity [5], United the date the mileage or credit was claimed to be earned [8], and Marriott Bonvoy the date of the applicable activity [4].
How long do I have to claim missing United Airlines miles?
Twelve months. Both the claim and the proof supporting it must be received by United within twelve months of the date the credit was claimed to be earned, and certain partners may apply different retro-credit claim periods [8].
How long does Marriott Bonvoy give for a missing-credit request?
Marriott Bonvoy requires missing-credit requests to be received within one year of the applicable activity, unless its programme rules or applicable supplemental terms state otherwise, and the request stays subject to its posting timelines and documentation requirements [4].
Can the same flight be claimed in two programmes?
Delta does not allow it: Delta flights, airline partner flights, hotel and car rental activity are eligible for credit in only one mileage programme and cannot be transferred once recorded [5].
What documents should I keep for a Delta SkyMiles claim?
Copies of tickets or ticket receipts and boarding passes, held until the credit appears on the statement; altered or illegible documents are not accepted [5].
Sources
Sources checked on 18 October 2026. The American Airlines AAdvantage, Alaska Airlines Mileage Plan and British Airways Club programmes, and hotel programmes other than Marriott Bonvoy, are not covered here.
- Marriott Bonvoy loyalty program terms and conditions (updated October 2026), checked 18 October 2026
- Delta SkyMiles mileage credit rules and conditions, checked 18 October 2026
- United MileagePlus program rules, checked 18 October 2026