这里所说的邀请函是给我国驻客户所在国家使馆的！是要盖公司章，然后邮寄给客户！下面我以前公司的格式，供参考 

LETTER                                         HEAD 

LETTER　OF　INVITATION

　　　　　　　　　　　　　　　　Date________

TO: P.R. CHINA EMBASSY IN  __________

GENTLEMEN:

MANY THANKS FOR YOUR HELP.WE ARE PLEASED TO INVITE OUR GUESTS: _________________________TO VISIT OUR COMPANY TO____________

DETAIL INFORMATION ABOUT OUR GUEST AS FOLLOWING:

NAME OF COMPANY: __________________________________IS A GOOD REPUTATED COMPANY IN ____________.____________ IS THE _________ OF  _____________AND ____________IS THE ____________ OF ___________

Name:   ___________

Date of Birth: ________________

Passport No.: ___________

Date of Expiry:__________

Name:   __________

Date of Birth: _____________

Passport No.: ____________

Date of Expiry: _________________

WE ARE VERY GLAD TO INVITE THEM　TO COME TO CHINA TO  ____________, SO　KINDLY  ISSUE THEIR VISAS. OUR COMPANY BOOKED ROOM IN FIVE STAR HOTEL FOR THEIR STAY.

THANKING YOU,

YOURS FAITHFULLY.

____________________

下面是我在以前公司给客户发的邀请函，可以参考。

           ******* 机械有限公司******************MACHINERY CO.，LTD

Add: ********************************, Jiangsu, China

　　　　　　　Tel: *****************Fax :*******************

LETTER OF INVITATION

September 5^th, 2005

TO: P.R. CHINA EMBASSY IN PAKISTAN 

GENTLEMEN:

MANY THANKS FOR YOUR HELP.

WE ARE PLEASED TO INVITE OUR GUESTS:MR. ABDUL GHAFFER AND MR. ABDUL JABBARTO VISIT OUR COMPANY TO INSPECT CHNEILL MACHINE.

DETAIL INFORMATION ABOUT OUR GUEST AS FOLLOWING:

NAME OF COMPANY: RAZZAR CHEMICAL COMPANYRAZZAR CHEMICAL COMPANY IS A GOOD REPUTATED COMPANY IN PAKISTAN.MR. ABDUL GHAFFER IS THE C.E.O OF  RAZZAR CHEMICAL COMPANY AND MR. ABDUL JABBAR IS THE CHAIRMAN OF RAZZAR CHEMICAL COMPANY

Name:   MR. ABDUL GHAFFAR

Date of Birth: 14 AUGUST 1961

Passport No.: K272335

Date of Expiry:18 MAY 2006

Name:   MR. ABDUL JABBAR

Date of Birth: 12 JUNE 1938 

Passport No.: K272337

Date of Expiry: 18 MAY 2006

WE ARE VERY GLAD TO INVITE THEM　TO COME TO CHINA TO INSPECT OUR CHENILLE MACHINES, SO　KINDLY  ISSUE THEIR VISAS. OUR COMPANY BOOKED ROOM IN FIVE STAR HOTEL FOR THEIR STAY.

THANKING YOU,

YOURS FAITHFULLY.

**************** MACHINERY CO.,LTD