是指坐美联航航班或星盟航班累积积分吗？新开的账户就能，甚至飞UA自己的航班还可以免费回溯一个月前的累积。申请会员之前飞的1个月到6个月之间的旧航段就要花钱才能挽回了。
https://www.united.com/ual/en/us/mileageplus/mileagecredit/Travel on United or United Express®Mileage and Premier qualifying credit (where applicable) should be reflected in your account within 48 hours after travel is completed. If your flight credit has not posted after five days, submit a request for credit using the form at the bottom of the page.
New MileagePlus members may request mileage and Premier qualifying credit (where applicable) for flights completed on United and United Express up to 30 days prior to their enrollment date. For a $50 USD fee, new members may request mileage credit for flights more than 30 days and up to six months prior to their enrollment date. Contact the MileagePlus Service Center to process this request.
Travel on Star AllianceTM member airlines and other partner airlinesFor flights on Star Alliance member airlines and other partner airlines, it may take up to 7 days for mileage and Premier qualifying credit (where applicable) to display in your account due to variations in processing times across the wide network of member airlines. View the full list of Star Alliance member airlines and other partner airlines.
If your credit has not been posted after 7 days, submit a request for credit using the form at the bottom of the page. In some instances, additional documents may be required to complete your request. If supporting documents are required, you will be prompted to upload files (.gif, .jpg, .pdf, .png or .tif).
+Exceptions for ANA, Azul and Eurowings;+ For ANA-operated flights within Japan that do not have a ticket number, enter "2050000000000" in the ticket number field. For Azul-operated flights within Brazil that do not have a ticket number, enter "5770000000000" in the ticket number field. For Eurowings-operated flights within Europe that do not have a ticket number, enter "1040000000000" in the ticket number field. If you have any other ticket receipts or boarding passes without a ticket number, please submit a request using the MileagePlus contact form.
