It is difficult to answer this question without saying “it depends”. It actually depends on the expectations you have with your outsourced provider and your clients.
For year-end accounts work many of our clients prefer to white-label our services. This means that it is our client’s responsibility to sort out the queries with clients for each year end accounts job. For bookkeeping work we actually recommend that our clients let their clients know that they have outsourced the bookkeeping work. This then allows us to directly liaise with their clients and stops our client being a bottleneck for bookkeeping queries.