首先说“一次性”付款，合同翻译中，常用“in the/one lump sum”，或者更简洁点，直接用“lump-sum”来表达。

lump-sum的英文释义可参考：an amount of money that is given in a single payment, rather than being divided into smaller periodic payments。非常符合中文中“一次性”的含义。

双语例句：

“任何股款的催缴，应当作是在董事会通过授权催缴股款的决议案时已作出，并可按一次性或以分期方式缴付。”

“A call shall be deemed to have been made at the time when the resolution of the Board authorising the call was passed and may be made payable either in one lump sum or by instalments.”

再来说 “全额”和“足额”。

“全额”和“足额”属同一个意思的不同表达习惯，常用来表示“全额”、“足额”的表达方式有“in full amount”、“in full”、“in the aggregate”、“in total”、“total”、等。

双语例句：

(a) 若因买方未按其分别与卖方、B公司、C公司及其他小股东签署的相关股份出售协议的约定按时支付各该等协议项下的股份收购对价出现迟延付款、且经各该等协议项下的股份出售方书面催告后1个月内仍未完成支付的，各方可友好协商；若友好协商不成，则由前述情形导致B公司未能与卖方共同行使拖售权完成本协议项下交易的，因此导致的违约责任由买方承担，届时卖方有权单方解除本协议且无需退还买方已支付的定金，但应退还已收取买方的全部股份收购对价。仅在因卖方未完成本协议第3.02条第(a)(1)(C)款第a)项和第b)项项下工作承诺的原因而导致本协议项下交易未能完成的，各方可友好协商；若友好协商不成，则卖方应全额退还买方已支付的全部股份收购对价和定金；若因卖方未完成本协议第3.02条第(a)款项下其他工作承诺事项的原因而导致本协议项下交易未能完成的，则卖方应按照第9.04条和第10.1条约定承担责任。

(a) In the event that Purchaser fails to pay on time the share acquisition consideration under any of the relevant agreements for sale of shares respectively with Seller, Company B, Company C and Other Minority Shareholders in accordance with any such agreement, and remains so within one (1) month upon written notice from the seller of the shares thereunder, the Parties may deal with such breach through amicable negotiations; should such negotiations fail, Purchaser shall assume any and all liabilities for breach for contract resulting from Company B’s failure to consummate the transactions hereunder by exercising the drag-along right together with Seller as caused by such breach, in which case Seller shall have the right to unilaterally terminate this Agreement with no refund of the Deposit already paid by Purchaser, but shall refund the total share acquisition consideration collected from Purchaser. Only to the extent of the failure of any transaction hereunder to be consummated resulting from Seller’s failure to complete the work commitments under Clauses 3.02(a)(1)(C) a) and b), the Parties may deal with such failure through amicable negotiations; should such negotiations fail, Seller shall refund the total share acquisition consideration and the Deposit, in the aggregate, already paid by Purchaser; in the event of the failure of any transaction hereunder to be consummated resulting from Seller’s failure to complete other work commitments under Clause 3.02(a), Seller shall be held liable therefor in accordance with Clauses 9.04 and 10.1.