I have two related tables (Table A & Table that are linked by one field: contact id (number field).

I would like to be able to use the contact id field in Table A. to check for a matching id in Table B.

Then, once I identify those records in Table A with matches, I would like to display them in a list layout.

I know how to display them but not sure how to check the two tables for matches.

I'm sure this is simple, but i can't think of anything now.

You can use GTRR (Go to related records) and in the GTRR options choose Show only related/Match all records in current found set.

So, if you're looking at all records from table A, and you GTRR/Match All to table B, you'll be looking at all B records that have a matching A record.

You can then GTRR/Match All from B back to A, and so that would give you all A records that have a B.