Hi..
welcome to the forum...
For the average sized domestic installation an EIC would normally have enough space on the "Schedule of test results" for all the circuits you have worked on..
so just write them all on the one EIC..
In the description box bit.. if there is not enough room just attach an extra bit of paper and note it..
i.e. see note on model forms where it says in brackets (use continuation sheet if necessary)
so in box titled "extent of installation covered by this certificate"
you could write "SEE ATTACHED SHEET 4 FOR DESCRIPTION OF WORK DONE"
Then just add any A4 sheet to the back of your EIC..
e.g.
Sheet 4 of 4.
New circuit 7 added for shower.
Existing circuit 2 downstairs sockets extended in lounge and conservatory 4 new sockets added.
Existing circuit 4 downstairs lights extended in lounge and conservatory 2 new lights added.
new RCD added to provide protection to circuit 4.
All other circuits (1,3,5 7 6) remain unaltered.
Guinness