Estimates of international migration, by individual quarter can be derived from the International Passenger Survey (IPS). However, these quarterly estimates are not fully processed survey data and as such are not official statistics. For more information regarding this decision, see International migration – terms, definitions and frequently asked questions (Section 10).
It is important to note that estimates by quarter are not as robust as our estimates for rolling years and are not official statistics. This is because of the small sample sizes involved and because the complete methodology applied to our estimates for full years cannot be applied to our estimates for individual quarters.
Owing to the seasonal nature of international migration and the small sample sizes involved for individual quarter data, users should be cautious with any interpretation of individual quarter estimates, especially where the corresponding confidence interval is large in comparison with the estimate.
Where these data are used, we advise users to only compare the individual quarter data with the same quarter in the previous years. However, given the limitations with quality, methodology and coverage, we recommend using the estimates for rolling years over the individual quarter data.”