To achieve this in simple way. Append [] to the name attribute. When the form is posted, List will be acptured in the model.

<input name="UserChannelIds[]" value="1" @(Model.UserChannelIds.Contains(1) ? "checked" : "") type="checkbox" />

<input name="UserChannelIds[]" value="2" @(Model.UserChannelIds.Contains(2) ? "checked" : "") type="checkbox" />

During edit, we can bind the "checked" attribute by adding the condition @(Model.UserChannelIds.Contains(2) ? "checked" : "")