I noticed that a change made in a custom field from a Customer, did also change the information in the custom field in Sales Invoices which Sales Invoices were already made.
Which is annoying.
It means that only the hard-copy of the original Sales Invoice has the right information.
On the other hand, a change made in e.g. the address of the customer does not change the address in the sales invoice which were already made. Which is fine.
Practice:
Client provide a Purchase Ordernumber which is valid for a year.
By changing the purchase ordernumber in the custom field, because client has provided a new purchase ordernumber for the new period, all the already made invoices show now the new purchase ordernumber.
Which only leaves the hard-copy of the then made sales invoice to have the correct information.
It would be nice if the info on the sales invoices already made stayed the same, unless changing the info on that specific invoice was intentionally done.
In the Settings of the programme, there are two options regarding Custom Fields.
On the one hand, Settings > Obsolete Features > Classic Custom Fields and, on the other, Settings > Custom Fields.
My comment relates to Classic Custom Fields. There I already created two fields with the same name, but linked to different Placements i.e. Customer and Sales Invoice. I think I acted exactly as you advised:
As far as I know, this always worked well.
Found the Upgrade option to convert de Classic fields to the new format. Will see how this works.
It’s possible that I have forgoten the behavior of Classic Custom Fields and it’s also possible that their behavior might have changed.
However, I do remember a long time ago, I’ve tested Inventory Items images using Custom Fields and the invoices seem to update as I updated these images.
I don’t know if this will have any positive effects in your case, but please share your results.