Engagement letters for a group of taxpayers

What's your practice for sending an engagement letter for a group of taxpayers? In other words, you have an individual client, his S Corporation, her S Corporation, the two (minor) kids, bookkeeping services for one of the corporations. Do you do one engagement letter for all of that? separate engagement letters for each one?

I prepare separate engagement letters for each S Corporation and one for the parents' individual returns.

I do one letter for the clients with the s corp, c corp, and bookkeeping...

And one letter for each of the kids.

So I have 3 total letters here.

Do y’all use templates provided by the aicpa? Another source?

I started with one copied from another firm (with permission) and have been adding to it ever since.

I do one letter for the clients with the s corp, c corp, and bookkeeping...

And one letter for each of the kids.

So I have 3 total letters here.

So then this question... when you write the one letter to cover the business and the individual and corporate returns, and the bookkeeping.. do you do a letter (with all the terms and conditions) that says you've been engaged to provide professional services that are listed on an attached addendum of services?

so on the addendum you list
Joe and Jane Smtih
Form 1040...
Hawaii individual return...
etc
Joe Smith Co
1120s
Hawaii...
bookkeeping...

or do you put all that in the one engagement letter?

I do separate engagement letters for each regarded entity. I might combine for an engagement for 1099 prep (I use a short engagement letter for that to make it clear I'm charging for prep and it's not included in income tax return prep).

At a firm I worked with previously, we did a combined 1065 engagement letter for one client that had 6 or 7 partnership entities.

I would not combined 1040, 1065, and/or 1120-S. A good engagement letter will have provisions that are geared toward the tax entity that is being engaged and will not apply to others.

I do one letter for the clients with the s corp, c corp, and bookkeeping...

And one letter for each of the kids.

So I have 3 total letters here.

So then this question... when you write the one letter to cover the business and the individual and corporate returns, and the bookkeeping.. do you do a letter (with all the terms and conditions) that says you've been engaged to provide professional services that are listed on an attached addendum of services?

so on the addendum you list
Joe and Jane Smtih
Form 1040...
Hawaii individual return...
etc
Joe Smith Co
1120s
Hawaii...
bookkeeping...

or do you put all that in the one engagement letter?

I have an engagement letter with a section that I customize based on several types of services, sort of like a menu. I can add or remove them for each one. Similar to the list you created above.

Then, the other sections have provisions for bookkeeping, as applicable (as engaged), for example.

The a section for payroll, if engaged.

These sections also mention that support for these services is not available if the client is not engaged for them.