Quick question (probably a stupid one) but if you have a yes/no field but don't state a default value does it automatically default to no. It would appear to but I just want confirmation.

Thanks.

No it does not. It defaults to "null" which is not no.

Thanks for that, that's what I thought. However when I do a query on a table that has 4 records on a Y/N field and set the criteria to "Is Null" I get no records returned but when I change the criteria to "No" I get 4 records? I haven't made any entry into the Y/N field.

By definition a boolean field can only be yes/no, for some reason Access decided to allow Null as valid. Either prevent the use of Null entries or use a different method.