That's true. Unfortunately it's all a bit of a shambles.
The bridging described in LASORS Section J1.9 is available from ATPL(H)/IR to ATPL(A), from ATPL(H) or CPL(H) to CPL(A) or for UK Qualified Service Poilots with CPL(H) and ATPL theory wishing to bridge across to ATPL(A). Notice there is no declared route to bridge from CPL(H) with ATPL(H) theory across to ATPL(A) theory unless you are a military pilot.
In theory, if you hold an ATPL(H)/IR you need to do a course and the following fixed wing exams:
Performance
Principles of Flight
Operational Procedures
(H) to (A) Bridging (100 questions as described above)
In reality, if you have completed the interim ATPL(H) course, you will have passes in all the ATPL(A) exams except Performance and P of F which are valid for 36 months after your last exam so, in that period, you are exempt Op Procedures and the Bridging paper and need only to sit the two you haven't done.
So what if you don't have an IR and you're not a military pilot but you have just finished the interim procedure as heliporto has, above? In the past common sense has been applied and the CAA have allowed you just to sit the two extra papers.
Right now we're in limbo. The CAA announced that, at the end of Nov 08, the interim procedure would start to be phased out. They said nothing about the application of these credits and have yet to answer direct questions about this sent by e-mail on the 11th of December. They did start to refuse applications to sit the extra two exams. We have complained and asked for clarification. I am led to believe that all decisions relating to the interim procedure are under review and I was told the CAA's position would be clarified in an AIC to be issued in early January 09.
Frankly, it's a mess.