If I understand correctly you need two constraints:
1. unique by all columns
ALTER TABLE [dbo].[MyTable] ADD CONSTRAINT [IX_MyTable_1] UNIQUE NONCLUSTERED
(
[ID] ASC,
[Accno] ASC,
[Type] ASC
)
2. unique by ID/Type
ALTER TABLE [dbo].[MyTable] ADD CONSTRAINT [IX_MyTable_2] UNIQUE NONCLUSTERED
(
[ID] ASC,
[Type] ASC
)