1 What that means for your itinerary
A trip that crosses the Cambodia border twice needs two applications: two US$66 government fees, two of our US$59.99 service fees, and two review windows of 5 working days each.
2 Apply for the second one before you go
Do not plan to apply for the return leg while abroad. You would be waiting 5 working days outside Cambodia (sometimes around 2 working days where faster handling is possible — on request, never guaranteed), on a trip that has already started.
3 Airside transit is a different question
Changing planes without clearing immigration is not usually re-entry. Passing through passport control is — and that is what ends a single-entry permit.
4 Check what you actually hold
Your approval states its entry type and its dates, and allows a stay of up to 30 days. Read it rather than assuming, and check it before you book anything that leaves the country.
5 Before you book a side trip
Work through the Cambodia eVisa requirements checklist, then continue to the application flow. Other questions for this destination are collected in the Cambodia eVisa FAQ.
United eVisa Services is a private application-support provider, not a government agency. The immigration authority makes the decision.