Book identification: 1990s children's book with robot and credit card

This is a longshot, because the book is at my parents house currently, but my gut is telling me that this might match Marilyn Z. Wilkes's C.L.U.T.Z. books. I only read the first one, entitled C.L.U.T.Z., but it did have a sequel, C.L.U.T.Z. and the Fizzion Formula, so it barely qualifies as a "series". The basic premise is that Rodney's family needs a housekeeping robot, but can't really afford a new one, but an unemployed Combined Level Unit/Type Z (aka a C.L.U.T.Z.) robot shows up on their doorstep after having been abandoned by his prior owner.

What ensues, from my memory, is a comedy of errors due to Clutz being, well, a klutz. He's well meaning, but bumbling. I particularly remember a sequence where he fixes their holovision set by moving scoops of crystals around inside, but a subsequent attempt to fix a floating bed goes awry. Clutz gets thrown out, and Rodney follows with him. I don't specifically remember the credit card, but there's a tickle in the back of my head that Rodney takes the family one with him when he runs away.

Ultimately, Rodney winds up in some disastrous situation after his parents acquire one of the fancy "Butler" robots that are the new thing, and said robot lacks the empathy (or maybe just the programming) to help him, while Clutz does save him, resulting in Clutz becoming part of the family.

The Internet Archive has a copy that can be borrowed, and your memory is correct about the "junior credit I.D.".

He went to the hall closet, took out his jacket, and stuffed it into the bag. Then he pulled a small plastoid rectangle out of his pocket and examined it. It was his junior credit I.D., which was issued to every U.F.N.A. child from six to twelve annums old. His had a fifty-credit spending limit, raised from forty on his last birthday. That wasn't much, but it would pay for a couple of days food and shelter if necessary. Rodney added it to his bag.