According to the WelFur assessment protocol for mink, welfare is assessed via three one-day visits; one during each of the three main annual production phases. If one of these three assessments could provide a representative description of the welfare on a mink farm throughout the year, not only would much time and money be saved, it would also provide the farmer with an immediate result. As the same manager is usually in place for all three production phases and as most of the welfare problems associated with mink production are related to management, we hypothesise that assessment in one of the three phases should be sufficient for predicting the overall annual classification of welfare on a farm. Based on the WelFur protocol for mink, data from 19 farms were collected in each of the three production phases: breeders during winter (assessment period one); females and kits in lactation (assessment period two); and juveniles during late growth (assessment period three). The data were recorded by two external assessors per farm, on nine farms in 2011 and ten other farms in 2013, and an aggregated welfare assessment at farm level was calculated for each of the three visits. Data from the three assessments per farm were compared both at criteria, principle, and at overall classification level according to the Welfur mink concept. It appears that the estimated WelFur classification of farms differs between assessment periods, especially as regards to low score-value of the principal 'Good Feeding' in the summer period. Scores from periods two and three are needed to predict the full annual score of the four WelFur principles. Based on the results found, we reject the hypothesis that the overall annual classification of welfare of a farm in the WelFur system can be based on one period. A simplification of the WelFur-assessment system may be possible, with the exclusion of the welfare assessment in period one.