a bill, a written statement of money owed

enclose

envelope

a strong request / a demand, a claim on the basis of some authority (especially for payment)

to make a demand or strong request / to make a demand on the basis of some authority, to make a claim

to send; to dispatch / to see off, to take (somebody somewhere), to escort / to play back / (linguistics) to add okurigana / to pass the time / to see off a deceased person

To send

imperfective and stem (or continuative) forms of 送る (okuru) [ichidan]

document

letter