What are the best answers for “subject to or requiring payment especially as specified”?

collectable, collectible, payable.

How many letters does the top answer for “subject to or requiring payment especially as specified” have?

The most common answer is collectable (11 letters).

3 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

collectable 11 letters wn-def

things considered to be worth collecting (not necessarily valuable or antique)

collectible 11 letters wn-def

things considered to be worth collecting (not necessarily valuable or antique)

payable 7 letters wn-def

a liability account showing how much is owed for goods and services purchased on credit