Guarantee Mortgage - San Francisco, 505 Montgomery

We have helped Bay Area families finance their home purchase, with over $2 billion in loans annually, and we can help you.

Offering a wide range of products and services, Guarantee Mortgage is well prepared to meet every real estate lending need.

We have 22 years under our belt providing world-class client service. Our top priority is to make sure you are presented with all available loan options, so that you can make an informed decision, that’s right for your financial situation.

Guarantee Mortgage NMLS #1850 and CAL-BRE License #01215943


Recommendations (1085)

Feb 11, 2020

Diane recommends Pov Oum

Pov did a great job with refinancing our loan, she returned calls and e-mails promptly. Yes I would recommend her. Thank you..
Feb 11, 2020

San recommends Pov Oum

Pov is Very professional ,efficient and friendly. I respect how hard she works and fast responses. Highly recommend and also many more year looking forward to work with her by any chance. Thank you so much for working with us.
Feb 8, 2020

Anonymous recommends Kathy Derangi

Kathy was great! She was super helpful in guiding us through the home loan process. She was very responsive, answered questions thoughtfully, and made the process really easy. As first-time homebuyers in this challenging market, securing the mortgage with Kathy was one of the easiest parts of the process. Thanks, Kathy!
Jan 29, 2020

Susan Lucas recommends Orlando Diaz

Orlando was amazing at overcoming the obstacles in getting my loan approved. I would highly recommend him!
Jan 23, 2020

Guillean Arradaza recommends Pov Oum


I’ve worked with Pov for over a year now and she’s proven that she is very knowledgeable, resourceful and patience with any client that I send her way. I admire her abilities and how she is super diligent with every single file. She helped me with my own mortgage loan and as a consumer, she checked all the boxes that I was looking for in a loan officer. I highly recommend her.
Jan 20, 2020

Gareth Davies recommends Orlando Diaz


Orlando was fantastic from start to finish. He helped us navigate a tricky re-finance with professionalism, patience and a sense of humor! Strongly recommend working with Orlando and would refer every time!
Jan 15, 2020

Robert Howard recommends Cecelia Tyeskey

Very happy to work with Cecilia on our refinance. It was complicated but she had the experience to deal with everything we had so it wasn't an issue for her. We are happy that she followed up on every detail directly and didn't hand off to someone unfamiliar with our loan. We also recommend Cecilia because she was clear and reviewed the options upfront before we had to commit to anything. Thank you!
Jan 14, 2020

Alex Lankston recommends Cecelia Tyeskey

Startup Founder

Cecelia is truly amazing. Having worked with her for 20+ years, I continue to be astounded by her can-do attitude and knowledge. No-one does it better - or is even close!
Jan 13, 2020

Jude Tumboko recommends Orlando Diaz

In a truly insane process, Orlando was the most helpful person someone could have hoped for. Orlando was knowledgeable & professional. Most of all he was kind and responsive. He really helped us along every step of our refinance. Orlando provided clear explanations of the terms and conditions of all of the paperwork. He was patient and made certain that our interests were protected during the whole process. All actions requiring his followup and intervention were handled. We are quite pleased with his performance, and the overall experience. We are beyond grateful that he was on our side.
Jan 9, 2020

Callie Williams recommends Orlando Diaz

Home owner

Orlando was with me through every step of my refi. He was quick to answer all of my questions and even followed through with questions I had after the loan was refinanced. I would use Orlando again and would recommend him to anyone looking to refi.
Jan 9, 2020

Cathleen Bowen recommends Orlando Diaz


Orlando was timely, efficient, pleasant and got the job done. I recommend Orlando!
Jan 6, 2020

Beth Eichenberger recommends Orlando Diaz

Nursing Director

Ww got it done- lots of hurdles- stars and stops, but Orlando stuck with me and it is mow done!
Dec 31, 2019

Refaee Alrefaee recommends Pov Oum

Retail business owner

This is the first time I have ever reviewed anyone
In life we come to meet certain people that impresses us in every possible way
POV Oum,
yes Pov Oum, is one of this people
The knowledge and experience she has has impressed me, and take it from me, NO OTHER BANKER knows how to make things run smooth and fast like Pov
It was a great honor to do Bussiness with her, and she will be my loan officer for years to come
She’s very well recommended
Thanks Pov for all the work you have done,
Dec 28, 2019

Robert Michael Olszewski recommends Kathy Derangi

Regional Sales Manager

We were delighted and can't say enough about how responsive Kathy was to all of our requests. She was attentive to details and worked to pull together options for the purchase of our home working continuously to get our closing in before the New Years holiday. It was clear throughout the process that she had our best interests in mind. We will use Kathy again and strongly recommend her to anyone of our friends looking for a new house or a refinance. I think Kathy is our new secret weapon for financing our home. My husband and I are grateful for everything Kathy has done, simply amazing!
Dec 27, 2019

Elinor Davies recommends Orlando Diaz

Orlando was thorough, professional and caring. Our process was long and difficult with lots of hurdles, and Orlando supported us through all and saw us through to the other side. Thanks Orlando!
Dec 23, 2019

Rick Estrada-Stone recommends Kathy Derangi

We have worked with Kathy for a number of years and have always received stellar service. Would definitely recommend to anyone looking for a loan or refi.
Dec 22, 2019

Anna Lee recommends Pov Oum

Super easy to work and communicate with. Thank you so much for all your help!
Dec 19, 2019

Marc Paschke recommends Aisling Ferguson

Executive Director

We have now used Aisling three times over 15 years. Simply put, she is the best. There is nothing that any one else could do that would be better. She knows everything there is to know. She explains everything I need to know. She gets everything done at lightning speed. She responds to emails and calls immediately. And I mean immediately. Most of all she is a nice person. Of all the people I have dealt with in a business setting, I have never dealt with any one that is as professional, efficient and awesome as Aisling.
Dec 19, 2019

Catherine Vowles recommends Aisling Ferguson

Regulatory Affairs Specialist

Aisling comes highly recommended. She is both a joy to work with and the most competent loan broker you could ask for. Fast, accurate, available and knowledgeable. I’ve used her twice and would not hesitate to do so again.
Dec 8, 2019

Philip Ho recommends James W. Argo

Loan Recipient

Jim came highly recommended to us for our financing needs, and he did not disappoint. He is experienced and knowledgeable and is a pleasure to work with. Jim kept us informed every step of way on our loan process and strategically procured the best interest rate, with the lowest amount of associated fees. His combination of business savvy and availability made us feel extremely confident that our needs were top priority. We would definitely use him again for any future transaction.
Dec 4, 2019

Brent Piattelli recommends Ken Dean

Ken IS THE REASON WE GOT OUR HOUSE. He made everything happen that we needed him to, and the loan was not an easy one so I was very impressed with how good he is at his job both knowledgeable and fast-paced. I would recommend Ken to everyone!
Nov 20, 2019

Jennifer recommends Joel Marks

We were pleased with the process from start to finish. Joel did a great job walking me through the process and ways always quick to respond to text, email and calls, esp when I had questions about numbers and paperwork. I would absolutely recommend working with Joel.
Nov 18, 2019

Jodie recommends Pov Oum

One of the best experiences of my life was dealing with Pov assisting me and getting my loan to my new house
Nov 18, 2019

Miriam recommends Joel Marks

Very straight forward and easy to work with.
Nov 12, 2019

Rita E Aguilar recommends James W. Argo

Jim was awesome from the beginning. In the beginning, he spent time getting to know us and explained to us how he can help us succeed in purchasing our home. I worked closely with Jim on my goals. He was available to answer all my questions. When we were ready. Jim and his team was on top of getting everything pushed and finished as soon as possible. He made this an easy process and we will definitely work with Jim again. Thank you Jim for your expertise and knowledge in the Home lending business. You will hear from us again.

Our Team

  • Bob Siefert

    Senior Vice President - San Francisco - Montgomery St.
    NMLS #55105 / 1850 - CA BRE #00921214 / 01215943

  • Orlando Diaz

    Sr. Loan Consultant - San Francisco - Montgomery St.
    NMLS #238849 / 1850 - CA BRE #01475255 / 01215943

  • Foster Weeks

    Loan Originator - San Francisco - Montgomery St.
    NMLS #253370 / 1850 - CA BRE #01383598 / 01215943

  • Allan McAllister

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #280540 / 1850 - CA BRE #01372084 / 01215943

  • Aisling Ferguson

    NMLS #280915 Loan Consultant - San Francisco
    NMLS #280915 / 1850 - CA BRE #01225420 / 01215943

  • Kevin Casey

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #238192 / 1850 - CA BRE #01178612 / 01215943

  • Mireille Costandi

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #249322 / 1850 - CA BRE #01132350 / 01215943

  • Ken Dean

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #237940 / 1850 - CA BRE #0902556 / 01215943

  • Larry Horowitz

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #239001 / 1850 - CA BRE #01003870 / 01215943

  • Amy Lai

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #341535 / 1850 - CA BRE #01795977 / 01215943

  • Ming Leong

    Loan Consultant - San Francisco - Montgomery St.
    NMLS # 252471 / 1850 - CA BRE #01369831 / 01215943

  • Natasha Lovas

    Senior Mortgage Advisor - San Francisco - Montgomery St.
    NMLS #239455 / 1850 - CA BRE #01161948 / 01215943

  • Paul Rea

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #280163 / 1850 - CA BRE #00856755 / 01215943

  • Cecelia Tyeskey

    Reverse Mortgage Specialist - San Francisco - Montgomery St
    NMLS #239861 / 1850 - CA BRE #01212004 / 01215943

  • James W. Argo

    Senior Loan Officer - San Francisco - Montgomery St.
    NMLS #257031 / 1850 - CA DRE #00869591 / 01215943

  • KC Murphy

    Sr. Loan Consultant - San Francisco - Montgomery St.
    NMLS #255492 / 1850 - CA BRE #1007053 / 01215943

  • Robin Patronik

    Senior Loan Officer - San Francisco - Montgomery St.
    NMLS #241087 / 1850 - CA BRE #01347330 / 01215943

  • Sally Adam

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #245703 / 1850 - CA BRE #01244582 / 01215943

  • Sheila Wood

    Manager/Loan Consultant - San Francisco - Montgomery St.
    NMLS #253742 / 1850 - CA BRE #00824166 / 01215943

  • Kathy Derangi

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #1151839 / 1850

  • Risa J. Meyer

    Mortgage Specialist - San Francisco - Montgomery St.
    NMLS #332214 / 1850 - CA BRE #01126851 / 01215943

  • Joel Marks

    Loan Advisor (NMLS: #216888/1850)

  • Fe David

    Loan Consultant - San Francisco - Montgomery St.
    NMLS # 482592 / 1850 - APMC CA BRE #01215943

  • Mark Wiener

    Loan Officer - San Francisco - Montgomery St.
    NMLS # 246293 / 1850 - APMC CA BRE #01215943

  • Pov Oum

    Loan Officer-San Francisco-Montgomery St.
    NMLS # 1226687 / 1850 - APMC CA BRE #01215943

  • Tra Thach

    Loan Consultant