Goods for resale acquired by travelers (sometimes called shuttletrade) are included in general merchandise in the Balance of Payments, whereasgoods acquired for personal use by travelers are recorded under travelservices. However, goods for own use acquired by travelers in excess of customsthresholds are included in general merchandise. The Balance of Payments Manual6th Edition (BPM6) states that this treatment is consistent with internationalmerchandise trade statistics, but that care needs to be taken to avoid doublecounting such goods by including them also under travel (see BPM6 para.10.19-10.20).
In practice, if the total values of goods acquired bytravelers over multiple trips is significantly above customs thresholds, thenunder such circumstances the compiler may wish to treat those goods asmerchandise rather than travel. And that the size of the phenomenon should beestimated/verified with border surveys and/or studies by customs.
Link to BPM6: https://www.imf.org/external/pubs/ft/bop/2007/pdf/bpm6.pdf